Wales centre Gavin Henson is a major doubt for Saturday's Anglo-Welsh Cup final against after Leicester limping off with a knee injury in Ospreys' defeat to Saracens.
Ospreys were left to lick their wounds ahead of Twickenham showdown after being dumped out of the European Cup at the quarter-final stage by Sarries.
The Watford-based outfit bounced back from their 30-3 Anglo-Welsh semi-final defeat to Ospreys a fortnight ago to beat the Welsh side 19-10 at Vicarage Road.
Coach Lyn Jones, who saw replacement Paul James score his side's only try, insisted there had been no complacency in the camp following last month's easy victory.
He said: "That really wasn't a factor today for us. We just didn't play as well as we can do. There were a lot of unforced errors from a lot of individuals. We have an opportunity next week to redeem ourselves.
"We have all seen thousands of games of rugby and it just wasn't our day today. And I don't want to take any credit away from Saracens, the way they applied themselves was how to win a game of rugby."
Cardiff Blues also went out of the competition, at the hands of French giants Toulouse, after a 41-17 defeat at Stade Toulousain.
London Irish are next up for Toulouse at Twickenham on April 26 after the Blues were blitzed by tries from Maxime Medard, Maleli Kunavore, Vincent Clerc and Jean Bouilhou.
Blues head coach David Young said: "We started to tire when they stepped up, and we can have few complaints about the result. I think we could have lost to the eventual champions.
"For anyone doubting Toulouse, they proved they are still a force in Europe with that performance.
"They had control, they were clinical and they kept the scoreboard ticking over. They have a great balance between their forwards and backs."
Peter O'Mahony was named man of the match against England last month
21 April 2017, 7:22pm
Peter O'Mahony's performance in the RBS 6 Nations finale for Ireland against England was crucial to his selection for the British & Irish Lions on Wednesday, Ireland and Lions defence coach Andy Farrell has revealed.