Kyle Schwarber played primarily left field for the Washington Nationals but is excited to give first base a try with the Boston Red Sox. Nick Wass/Associated Press

ST. PETERSBURG, Fla. — Newly acquired slugger Kyle Schwarber is looking forward to the challenge of playing first base for the Red Sox.

Boston plans to take a serious look at Schwarber playing the unfamiliar position when he is ready to return from a hamstring injury,

“For me, I view myself as a pretty good athlete,” Schwarber said Saturday before the Red Sox played at Tampa Bay. “I’m not a guy that’s going to shy away from something. I just want to be able to go out there and make sure you have the basics down. I know that, obviously, there’s a sense of urgency here where the club’s at.”

Boston began Saturday leading the AL East by a half-game over the Rays.

Schwarber was acquired Thursday from Washington for a minor league pitcher.

“It’s definitely a little whirlwind there,” Schwarber said. “Getting the call late that night and trying to scramble and make sure you get everything in order.”

He expects to start a minor league rehab assignment “pretty soon.”

“I think it’s not going to be too long,” Schwarber said. “Trust me, I’m itching to get back out. It’s been too long and I’m ready to get back out there and play baseball.”

Schwarber, who is hitting .253 with 25 homers and 53 RBI in 72 games, last played on July 2. He hit .412 in the 2016 World Series, helping the Chicago Cubs win their first championship since 1908, after playing just two regular-season games in early April before tearing the ACL and LCL ligaments in his left knee.

Schwarber is not the only key reinforcement expected to join the Red Sox in August.

Left-hander Chris Sale allowed one run and five hits over five innings in an 81-pitch outing during his fourth rehab start with Triple-A Worcester against Buffalo on Saturday as he continues his comeback from Tommy John surgery. He struck out seven and walked one.

Sale last pitched in the majors on Aug. 13, 2019, at Cleveland.

• The Red Sox placed left-handed reliever Darwinzon Hernandez on the 10-day injured list because of a right oblique strain.

“We don’t think it’s something that is going to take too long,” Red Sox Manager Alex Cora said. “He’s been dealing with it. He wanted to keep pushing it. So hopefully he can come back sooner rather than later.”

The Red Sox activated trade acquisitions Austin Davis and Hansel Robles. They optioned Connor Wong to Triple-A Worcester.

Boston acquired Davis, a left-handed reliever, from the Pirates for Michael Chavis on Friday. Boston got Robles, a right-handed reliever, from the Twins, for pitching prospect Alex Scherff, who was with the Sea Dogs.

Robles, 30, has a 4.91 ERA, 4.82 FIP and 1.39 WHIP in 45 outings for the Twins this season. He has posted a 4.03 ERA in 358 career outings.