The Red Sox have two new big names on their list of free agents.

Alex Bregman officially opted out of his contract Monday, a league source told the Globe, putting him on the open market for the second time in as many offseasons. And Lucas Giolito declined his end of a mutual option, another league source said, meaning he will be looking for a new contract, as well — perhaps with a qualifying-offer twist.

Technically, Bregman and Giolito could have waited until Thursday — the deadline for such matters — to do so. But neither move was a surprise.

The widespread belief throughout baseball at the time Bregman signed his three-year, $120 million contract in February was that he would give free agency another go after the season, and a source reiterated last month that Bregman planned to opt out.

Bregman, who will be 32 next season, batted .273 with a .360 on-base and .462 slugging percentage in 2025. His splits before (.299/.385/.553) and after (.250/.338/.386) a quadriceps injury suffered in late May were drastic. He finished with 18 home runs and 62 RBIs, and drew rave reviews from teammates and Sox bosses for his defense and leadership.

“Obviously, Alex has the right, as structured in his contract, to opt out and he’s going to do what’s best for his family,” chief baseball officer Craig Breslow said in October, after the Red Sox’ season ended. “I will not miss an opportunity to talk about his contributions on the field, in the clubhouse, to the coaching staff, to the front office. Every conversation we’ve had, I learned something. I think that impact and influence has rubbed off on his teammates, and by all accounts, he’s loved his time in Boston, as well.

“We’ll let that play out. But the significance would be having a great player, a proven winner, a strong defender, someone who fits this park really well on our roster.”

Lucas Giolito fought through elbow discomfort, as the regular season wrapped up, and ultimately was unavailable to the Red Sox during the Wild Card Series.Barry Chin/Globe Staff

Giolito, 31, will receive a $1.5 million buyout instead of a $19 million salary.

The next Giolito decision will belong to the Red Sox: Will they give him the one-year, $22.025 million qualifying offer? The deadline for that is Thursday. If they choose to do so and Giolito signs with another club, the Sox would receive an extra draft pick as compensation.

Giolito had a 3.41 ERA and 1.29 WHIP this past season, excelling from June onward to help solidify the rotation behind ace Garrett Crochet. Giolito encountered an elbow issue that sidelined him for the playoffs, but he and the team believed it to be minor and not related to the surgery that cost him the 2024 season.

Bregman and Giolito joined the Sox’ other free agents, whose contracts expired Sunday: Rob Refsnyder, Justin Wilson, Steven Matz, and Dustin May.

Among the biggest early-offseason uncertainties for the Red Sox is the fate of Trevor Story, who also can opt out of the final two years of his contract. He said on the day the season ended that “I came here to be here for a long time.”

West Coast fans “need to get used to more 3 and 4 p.m. start times, because the late nights on the East Coast are hurting the sport,” said Ben Volin.

Tim Healey can be reached at timothy.healey@globe.com. Follow him @timbhealey. Peter Abraham can be reached at peter.abraham@globe.com. Follow him on Bluesky at peteabeglobe.bsky.social‬. Alex Speier can be reached at alex.speier@globe.com. Follow him @alexspeier.