SEATTLE -- Rookie outfielder Braden Bishop remained hospitalized on Thursday after undergoing a procedure on his lacerated spleen. The Mariners are unsure on the timeline for his possible return.

The 25-year-old was hit in the ribs by a 97 mph fastball in his final game with Triple-A Tacoma on Friday -- a game in which he went 2-for-4 with a home run and four RBIs. Bishop was then recalled by the Mariners on Sunday after they traded Jay Bruce to the Phillies.

Bishop entered Sunday’s game as a defensive replacement for the final two innings and went 0-for-2 in two at-bats, then struck out in his first two at-bats when he got the start Tuesday against the Astros, before feeling intense pain in his left shoulder after making a catch in the fourth inning.

He initially was believed to have a cramp in his trapezoid muscle, but further tests revealed a lacerated spleen, which sometimes shows as pain in the left shoulder, as well as dizziness.

Manager Scott Servais said he wasn’t sure yet when the former University of Washington standout would be released from the hospital.

“They want to keep an eye on him and continue monitoring how he’s progressing and moving along,” Servais said. “I know he had some procedures done and may be in there for another day or two.”

Servais said he’d never heard of a player suffering an injury to an internal organ from being hit by a pitch.

“He’s very, very tough,” Servais said. “A couple doctors said he shouldn’t have been playing with this. But you get called to the big leagues, you want to play.”

Bishop, the Mariners’ No. 11-ranked prospect per MLB Pipeline, is 2-for-24 in his first season in the big leagues, but was figuring to get increased playing time in center field with Servais looking to improve the club’s outfield defense.

With Bishop now sidelined, Servais has moved Mallex Smith to left field, with right fielder Mitch Haniger taking over in center and Domingo Santana flipping from left to right. That alignment worked well in Wednesday’s 14-1 victory and Servais said he’ll stick with it for now, with newly signed Mac Williamson backing up at the corners.

“We’ll just have to watch it for awhile, but we’ll stay this way,” Servais said. “I’m not going to switch it back tomorrow or anything. We’ll stay this way for awhile, and see where it goes.”

Worth noting

• Hunter Strickland, sidelined since late March with a right lat strain, threw a 25-pitch bullpen session on Thursday and said it went “awesome.” The veteran closer will throw off the mound again Sunday in Tacoma and then join the Triple-A club for a rehab stint when the Rainiers begin a road trip in San Antonio on Wednesday.

• Felix Hernandez, who has missed three and a half weeks with a less severe right lat strain, also threw a bullpen session Thursday and said all was good after he tossed 15 pitches, then took a break before throwing another 15 to simulate a two-inning situation. He’s expected to throw live batting practice next in Tacoma and then could be ready to begin a Minor League rehab stint.

• Infielders Ryon Healy (lower back), Dee Gordon (bruised right wrist) and J.P. Crawford (sprained left ankle) all remain on schedule to begin Minor League rehab assignemnts at some point this weekend, according to Servais. All could potentially rejoin the Mariners toward the end of the team’s upcoming 10-day road trip.

• Right-handed reliever Chasen Bradford will remain shut down from throwing for likely another week or more, as he rests a strained right elbow. An MRI this week revealed a Grade 1 strain in his flexor area, but he’s hopeful of returning in about a month, if all goes well.

Fellow right-hander Connor Sadzeck is also dealing with a right elbow strain, but could begin throwing again Friday. Both Bradford and Sadzeck went on the 10-day injured list earlier this week.