Munster head coach Johann van Graan is bracing himself to be without three of his Six Nations internationals as well as Gavin Coombes for the first leg of their Heineken Champions Cup last 16 against Exeter on Saturday.
Andrew Conway, Tadhg Beirne and Dave Kilcoyne all missed Saturday's 35-19 defeat to Leinster at Thomond Park, while Coombes suffered a first half ankle injury.
The number 8 was withdrawn after 27 minutes having briefly attempted to play on with the injury.
He appeared on the sideline with his ankle in a protective boot and using crutches, and while Van Graan was reluctant to guess a timeframe on the recovery, he didn't sound confident about the back row's chances of returning in time for the away leg at Sandy Park.
"He's obviously a very important player for us. You saw at the start of the game I thought he carried really well. It's a big concern for us with what's ahead," Van Graan said.
The South African has all but ruled Conway out of this week's first leg, while said he would be "pretty worried" about fellow internationals Beirne and Kilcoyne, who both returned from the Six Nations camp with knocks.
However, he seemed hopeful Simon Zebo, Mike Haley and Jean Kleyn could return this week.
"Andrew Conway, it's safe to say he won't make next week. Pretty worried about Tadhg [Beirne] and Dave [Kilcoyne], we'll wait until Monday and see how they are.
"Hopefully, JK [Jean Kleyn], Mike [Haley] and Zeebs [Zebo] will be back in. I'm more hopeful for them but I don't want to speculate tonight.
"Hopefully we get some good news because in knock-out rugby you need your best players on the pitch."
Van Graan lamented his side's first half discipline, after they failed to adapt to referee Christophe Ridley's interpretation of the breakdown, conceding six first half penalties at the ruck.
And despite being outscored four tries to one by their biggest rivals, he believes they learned enough from the defeat to be able to bounce back in the Champions Cup.
"The frustrating thing was that we couldn't adapt quickly to the referee who I felt had a good game, no issues.
"We are going to have a different referee to deal with next week, that's part of the game and we've got to figure that out and be better.
"In terms of the power, I think we dealt well with the power but the issue was that we gave them so many opportunities to gain access.
"I wouldn't say it’s a psychological blow.
"From our perspective you’ve got to look at the game the way it is and I felt we weren’t outplayed tonight. We were beaten by the better team.
"Unfortunately if you concede so many penalties, the penalties come from pressure.
"Look, you’ve got to give that to them. Their kicking game was excellent. I thought their set-piece was good.
"We felt actually we did very well in the scrum battle, they won their line-out ball, we lost a crucial lineout in a crucial time and then it comes down to small margins.
"That’s the game of rugby and they are currently the best team so we’ve got to be better across 80 minutes to beat them, and like I said, the example of that is getting ahead, 12-11 with one minute to go (to half-time) and we concede a penalty. I think that’s on us. We need to be better," he added.
