Jamie George limped off with a hamstring problem late in Saracens' 32-24 European Champions Cup defeat to Castres, leaving him a doubt for the Six Nations to compound a miserable week for the England hooker.
He was replaced as England captain by team-mate Maro Itoje when Steve Borthwick was named in the Six Nations squad on Tuesday, then suffered an injury at StoneX Stadium which puts his participation against Ireland on February 1 in doubt.
George came front row for two Theo Dunne tries in the 55th minute but was forced off in the closing stages with Saracens unable to indicate the extent of the damage.
“Jimmy has injured his hamstring. We're not quite sure how serious the hamstring injury is at the moment,” director of rugby Mark McCall said.
George's late withdrawal and a serious knee injury to Toby Knight added to a frustrating afternoon in north London, as Castres finally won after 21 successive away defeats in the Champions Cup.
The defeat was damaging for Saracens, as they progressed past the last 16 at home with defeat and must now travel to face Toulon.
“It was a really bad performance from us,” McCall said. “Custer deserved to win the game and we got what we deserved too, which is hard to say.”
“Our mentality for some reason wasn't quite right and that's on me and the coaches. It was a really disappointing day. Custer definitely outplayed us. They were really ready for the game.”
“We had a lot of the ball but we were poor with it and they defended comfortably against us. Then they scored when they had chances. It was a disappointing day.”
“All 15 players they brought in have played in the last five weeks, but not together.
“It wasn't a bunch of kids, they were proper rugby players and we tried to get that across to the team. We weren't quite there mentally.”
Scotland captain Tuipulotu is also a doubt for the Six Nations with a chest injury
Scotland coach Gregor Townsend is facing a sweat ahead of the Six Nations as well after key duo Sione Topoluto and Scott Cummings appeared due to injury concerns ahead of the tournament.
There is particular concern about the fitness of captain Tuipulotu, who has suffered a pectoral injury, with Glasgow coach Franco Smith hinting – but declining to confirm – that he fears a prolonged period of time out.
The 27-year-old played no part in Saturday's defeat to Harlequins in the European Champions Cup.
When asked for an update on Tuipulotu immediately after the match, Smith said: “He had an assessment. I don’t know the extent of that assessment yet.
“I think he might have been hit in the chest. It was a weird injury. It was just something that happened. We didn't suspect it, we just wanted to make sure it wasn't serious. But we'll have more clarity tomorrow.”
Asked how big of a hit it would be if Tuipulotu – widely expected to be part of the British and Irish Lions squad this summer – missed any or all of the tournament, Smith said little to ease concern that the influential full-back was in trouble. Period on the margin.
“It's not just the player, but as a person and a player in our environment, he brings a lot of confidence to the people around him,” he said.
He added: “So, I think it would be a loss for everyone if the injury was that serious, but I can still think that there is enough of the season ahead for him to be able to contribute, so I hope it is not such a serious injury that it will happen.” be particularly long.
He added: “He will go to the Scotland camp and will be managed by the medical team as well, so as a team, all communications will be made once we have clarity on the outcome.”
“I'll just say I don't know right now, let's see what the result says.”