George Kruis will miss England's summer tour to South Africa, Saracens boss Mark McCall has said.
British & Irish Lions lock Kruis will undergo surgery on an ankle problem at the end of the campaign, ruling him out of June's three-Test series against the Springboks.
Kruis will be available for Saracens' Aviva Premiership playoff run, but his summer surgery means Eddie Jones will be without six front-line stars on tour.
Billy Vunipola came through his first action in three months unscathed as Saracens secured a home semifinal with their 51-14 win at London Irish.
"He's not going to tour, no," said Saracens rugby director McCall, of lock Kruis.
"He's going to have surgery at the end of the season."
Saracens racked up seven tries to dismiss already-relegated Irish in Reading, setting up a home semifinal with either Newcastle or Wasps.
Sarries boss McCall confirmed Vunipola should start next weekend's final regular-season Premiership clash at Gloucester, in a bid to drive the No. 8, 25, back to full match fitness.
Vunipola has not played Test rugby since March 2017, after a broken arm in January compounded previous knee and shoulder problems.
McCall admitted Vunipola has endured some dark mental challenges since that broken arm suffered in the 15-15 Champions Cup draw at Ospreys on Jan. 13.
"It's good to get him back on the park," said McCall.
"We'll try to give him as much game time as we can next week, start him I'm sure against Gloucester next weekend, all being well. It's a shame it's a fallow weekend after that.
"He'll be a bit nervous next week, he's only played three games in total this year.
"He's done a hell of a lot of rehab, so it's good to get some of the walking wounded back.
"I don't think anyone sees it, but it was really tough when he broke his arm. He was very emotional straight after that.
"But he just believes that whatever will be will be, things happen for a reason but now he's back and doing what he likes best.
"We've got a training week the week after Gloucester and we'll make that week as tough as it needs to be."