Manager Torey Lovullo offered clues as to what the Diamondbacks’ reasoning was with their decisions to option right-hander Kevin Ginkel and infielder Jordan Lawlar to Triple-A Reno this week.

With Ginkel, he said the club felt he had become too reliant on his slider and needs to get back to using both his sinker and fastball more effectively.

“It’s about throwing a ball to where you want to with the movement and velocity that he has that’s going to get him back to this level,” Lovullo said. “I said, ‘I want to see you back here on the 16th day. That’s the goal. You’re getting sent down to go down and start to make improvements.’”

Ginkel, who missed the first month of the season with shoulder inflammation, has not looked like his old self since returning. He has logged a 12.60 ERA in 10 innings, giving up runs in six of his 13 appearances.

Lawlar struggled on both sides of the ball, most notably at the plate, going 0 for 19 in limited action since getting called up earlier in the month.

Lovullo said he did not believe the inconsistent playing time was a good rationale for the quality of at-bats Lawlar gave them.

“I talked to him about that in my office as we were sending him down,” Lovullo said. “That should not be used as a reason for him not going up there and having more successful at-bats. Having a successful at-bat is controlling the zone, swinging at balls vs. strikes. In my opinion, that’s a new role for him and it might be hard for him to adapt to.”

Lovullo added: “What I want him to do is swing at strikes. I want to control the zone, set up pitchers, get the pitch you’re looking for and have an all-field approach. We saw a lot of bat speed. But we saw a lot of swing-and-miss and he was very predictable on the pitch he was looking for, he was one-dimensional on the fastball and that’s just not going to work here at the big-league level.”

Lovullo elevates Perdomo to No. 3 hole

Lovullo has always liked having Geraldo Perdomo hitting in line with Corbin Carroll and Ketel Marte. He is keeping the three together, only Perdomo is not hitting ninth anymore. He’s hitting third, behind the 1-2 punch of Carroll and Marte.

That, at least, was the arrangement Lovullo had on Friday night, May 30, for the Diamondbacks’ series opener against the Washington Nationals.

“I felt like he’s one of our best hitters and he deserves to get that extra at-bat,” Lovullo said. “A player that’s hitting third gets more at-bats than a player that’s hitting ninth.”

Lovullo was asked why he didn’t have Perdomo ahead of the other two and he said one consideration was Marte’s personal preference.

“Marte likes to hit second against righties and first against lefties,” Lovullo said. “He doesn’t like to hit third at all.”

Lovullo continued: “I feel like I’m sandwiching guys that are patient vs. guys who may be a little more of free swingers. Look at the lineup and you can tell who is more of an early-go swinger and who is somebody that is very patient. I’m trying to build a little bit of depth in that area where we’re not having eight- or nine-pitch innings.”

Joe Mantiply designated for assignment

In need of an open spot on the 40-man roster, the Diamondbacks designated struggling left-handed reliever Joe Mantiply for assignment on May 30, potentially cutting ties with a longtime member of their bullpen.

Mantiply has had a brutal season. In two stints in the majors, he has allowed 17 earned runs in 9 ⅔ innings. He has not had an easy go in Triple-A Reno, either, logging a 5.56 ERA (seven earned runs in 11⅓ innings). He allowed three home runs in his most recent appearance with Reno.

Mantiply, who was named to the National League All-Star team in 2022, has had up and down stretches during his Diamondbacks tenure, but he also enjoyed some big moments, including recording several key outs in the postseason during the club’s World Series run in 2023.

The Diamondbacks have seven days to trade or release Mantiply or place him on waivers.

The club needed to open a 40-man roster spot in order to find room for both infielder Ildemaro Vargas and reliever Jeff Brigham, both of whom were added to the roster on May 30.

Nationals at Diamondbacks, 6:40 p.m., Cox, Ch. 34

Diamondbacks RHP Merrill Kelly (5-2, 3.52) vs. Nationals RHP Jake Irvin (4-1, 3.42).

At Chase Field: Kelly was cruising against the St. Louis Cardinals in his most recent start before running into trouble in the seventh inning, giving up a single, walk and double to open the frame before departing. … It was not a quality start, but it was the latest in a string of solid performances for Kelly, who has logged a 2.45 ERA in 55 innings over his past nine starts. … He did not face the Nationals when the Diamondbacks were there in April. He last faced them in 2023, holding them to one run over seven innings with just one walk and 10 strikeouts. … Irvin, 28, in his third season in the Nationals rotation, has been a serviceable back-end type through this point in his career. He was a fourth-round pick by the Nationals out of Oklahoma in 2018. … He was impressive his last time out, shutting out the Giants over eight innings in an outing that ranks among the better starts of his career. … He faced the Diamondbacks in April, giving up four runs in five innings. RF Corbin Carroll homered twice off him. … He averages about 91-92 mph with his fastball and leans heavily on his curveball, which has held opponents to a .185 average.

Coming up

Saturday, May 31: At Chase Field, 7:10 p.m., Diamondbacks RHP Brandon Pfaadt (7-3, 3.90) vs. Nationals RHP Michael Soroka (1-3, 5.61).

Sunday, June 1: At Chase Field, 1:10 p.m., Diamondbacks RHP Corbin Burnes (3-2, 2.72) vs. Nationals LHP Mitchell Parker (4-4, 4.65).

Monday, June 2: Off.

Tuesday, June 3: At Atlanta, 4:15 p.m., Diamondbacks RHP Ryne Nelson (2-1, 3.79) vs. Braves TBA.

What to know about the Washington Nationals

The Nationals entered their series finale against the Seattle Mariners on May 29 with a 25-30 record. They own the National League’s fifth-worst offense at 4.27 runs per game and the third-worst pitching staff with a 5.04 ERA. One thing they do have going for them is LF James Wood, who already is looking like one of the better players in the league. The 22-year-old slugger has a .287/.380/.569 line with 15 homers and eight steals. He was part of the RF Juan Soto trade with the Padres in 2022. LHP MacKenzie Gore, another part of that deal, has a 3.47 ERA through 11 starts. RHP Kyle Finnegan has a 2.41 ERA and has converted 15 of 18 save chances, though he blew his last chance last week vs. Atlanta.