DETROIT — Bat met ball and, under his breath, Astros manager Joe Espada muttered an expletive. The Detroit Tigers’ winning run stood at first base in the bottom of the ninth inning of a 3-3 game when Matt Vierling’s line drive seemed destined for the left-center field gap in Comerica Park’s expansive outfield.

Playing defense here tests athleticism and ability like few other ballparks in the sport. A converted infielder still conquered it. Making his 60th major-league appearance as an outfielder, Brice Matthews made a wonderful read on Vierling’s 328-foot fly ball, used his 82nd-percentile sprint speed to get into the gap and made a sliding catch to preserve Houston’s chance at a fifth consecutive series victory.

Josh Hader, Hunter Brown, Christian Walker and Isaac Paredes teamed to secure Sunday’s series-clinching 7-5 win, but that is their expectation. All four are premier players on this top-heavy team — a quartet the Astros need to win games.

Hader survived a laborious outing to strand the bases loaded in the ninth, Paredes tied the game with a solo home run in the eighth and Walker won it with a three-run shot in the 10th. Those are the sort of heroics Houston needs to maintain its place in a mediocre American League. Winning on Sunday left the Astros just a half-game back of the league’s final playoff spot.

Matthews’ catch is the type of contribution that can propel this club to something higher. Depth has long been the biggest concern for a team that boasts an American League MVP candidate, a reigning Cy Young finalist and a six-time All-Star closer.

The team can address some of its deficiencies at the trade deadline, but the Astros don’t have the prospect capital — or perhaps the financial appetite — to fix all that ails them. That reality makes players like Matthews invaluable, even if he sports a 32.7 percent strikeout rate and a .566 OPS.

Matthews is part of an outfield that is producing almost nothing offensively. That it is still blossoming into one of baseball’s best defensive units is important. Teams with depth deficiencies must maximize everything on the margins and search for every possible advantage. Matthews, and the rest of Houston’s outfield, provides one on defense.

According to Baseball Savant, 34 major-league outfielders entered Sunday worth at least two outs above average. The Astros employ three of them: Matthews, reigning Gold Glove finalist Cam Smith and Jake Meyers. Smith’s stupendous catch started an inning-ending double play Wednesday in Toronto helped preserve a tenuous two-run lead and secure that series win. Meyers has long been one of the sport’s most underrated defensive center fielders.

Among American League teams, only the Boston Red Sox and Tampa Bay Rays have outfields worth more outs above average than the Astros. According to Sports Info Solutions, the Astros are turning 69.8 percent of balls hit in the air into outs. The major-league average is 67.9 percent. Just three outfields have a 70 percent conversion rate. For an Astros pitching staff that surrenders the third-highest fly-ball rate of any team in the sport, this matters.

“All the small, little plays just to give us an opportunity to hit or hand the baton to somebody else. It matters,” Espada said Sunday. “When you’re trying to win games, we need contributions from everyone.”

The rotation gets crowded

Injured pitchers are permitted a maximum of 30 days on a minor-league rehab assignment. Cristian Javier made the first of his five rehab starts on June 3, meaning the Astros must decide what’s next for the oft-absent right-hander by Friday.

Javier needed 85 pitches to spin six scoreless innings for Triple-A Sugar Land on Saturday night. That he made the start at all signaled at least some uneasiness about Javier’s readiness to rejoin the major-league rotation.

Team officials had considered starting Javier during this weekend’s series against the Tigers, but opted for a fifth minor-league start “to work on some things that he’s still working on,” Espada said.

On Saturday, Javier’s four-seam fastball sat at 91.8 mph — one mile per hour slower than his season average — but he still generated 11 swings and misses on the 30 swings taken against his fastball and changeup. Javier threw 47 percent of his pitches in the strike zone and, of the 15 balls in play he allowed, just three came off the bat at 95 mph or faster.

“He threw the ball really, really well,” Espada said Sunday morning.

Other than to say “we’re going to sit down and talk about what’s next for him,” Espada declined to divulge much about Javier’s next steps. The right-hander is in the fourth season of a five-year, $64 million contract extension and is the second-highest paid starting pitcher on Houston’s roster.

That alone almost cements Javier’s spot in Houston’s major-league rotation — or at least ample runway to prove he deserves it. Because he pitched for Sugar Land on Saturday, Javier could start Friday’s series opener against Tampa Bay on five days of rest.

If he does, the Astros will confront a fascinating roster crunch. With two off days between now and the beginning of the All-Star break on July 13, the club might not need a six-man rotation, and the lack of roster flexibility within Houston’s bullpen raises questions about whether a starter’s roster spot could be in peril.

Three members of Houston’s bullpen have minor-league options: AJ Blubaugh, Bryan King and Miguel Ullola. King is the team’s setup man and in no danger of a demotion.

Blubaugh boasts a 3.52 ERA across 53 2/3 innings — more than any other Astros reliever has thrown all season. Seventeen of Blubaugh’s 33 outings have lasted two or more innings. His workload and efficiency have been invaluable, and demoting seems unlikely.

Logic, then, suggests shipping Ullola back to Sugar Land after he received his first major-league call-up on Sunday. Perhaps another reliever is dealing with an injury that will require an IL stint and could open a roster spot for Javier.

However, either of those options would leave Houston one reliever short in a bullpen that just shouldered a seismic workload during this seven-game road trip.

A more practical solution might be to shift a starter to the bullpen for at least one trip through the rotation, similar to what the team did with Mike Burrows earlier this month.

Burrows, who has a 5.48 ERA after 85 1/3 innings, is scheduled to start Tuesday against the Minnesota Twins, so it stands to reason he wouldn’t be available for another bullpen move.

That could leave Spencer Arrighetti as the most viable option to switch, should Houston decide to do it. Arrighetti, who won American League Pitcher of the Month in May, has a 9.00 ERA across 25 innings in June. He surrendered eight runs and secured nine outs in Friday’s loss to Detroit, after which the normally affable Arrighetti acknowledged he had few answers for his struggles.

Arrighetti is scheduled to make his next start Friday, the same day Houston must make a decision about Javier. The club could start Arrighetti on Friday and Javier on Saturday, but would it be beneficial for Javier to go a full week between starts? Ditto for ace Hunter Brown, who in this scenario would have his next start pushed back to Sunday.

Bear in mind, too, that Arrighetti and Burrows have minor-league options remaining. That could perhaps create more pressure for Burrows to have a strong outing Tuesday, or create an interesting conversation around Arrighetti.

Teng gets a ‘breather’

The Astros demoted Kai-Wei Teng to Triple-A Sugar Land on Sunday. That means three of general manager Dana Brown’s six offseason pitching additions have either been sent to the minor leagues or taken off the Astros’ 40-man roster. Combined, the sextet has posted a 5.41 ERA in 241 innings.

In a season where optics matter more than most, that’s a problem. Working in the final year of his contract amplifies any of Brown’s successes and failures. For the season’s first two months, he could tout Teng as an unquestioned success.

Teng’s past five outings should not change that. Before them, he boasted a 2.57 ERA and separated himself as a trustworthy arm capable of throwing multiple innings.

Teng’s recent stumble probably could’ve been foreseen as a result of an increased workload that arose out of necessity. Stretching Teng out as a starter is something Brown envisioned upon acquiring him, but doing so during the season in response to injuries is a difficult task. That Teng could even accomplish it and have some success speaks to his value and adaptability.

Teng, who has started and relieved in his professional career, threw a career-high 136 1/3 innings with Double-A Richmond in 2022. He hasn’t thrown more than 86 innings in any season since 2023. It’s not even July, and Teng has already thrown 64 innings this season.

“I would say there is some fatigue,” Teng said Saturday through an interpreter, “but it’s still manageable.”

According to Espada, part of the Astros’ rationale in optioning Teng to the minors was to give him a “de-load” and a “breather.” Teng is still going to pitch, but the team is still discussing exactly what that will look like and whether it will be as a starter or reliever.

In whatever role, expect Teng to be on a strict innings limit and pitch count for his next few outings at Triple-A Sugar Land. The goal is to refresh Teng and then return him to a major-league pitching staff that needs his skillset.