Wasps director of rugby Lee Blackett described Joe Launchbury's knee injury as "gut-wrenching moment" and admitted he fears it will keep the captain off the pitch for a lengthy period.
Launchbury took a blow to his left knee before half-time in Wasps' 39-29 win over Bath at the Ricoh Arena and was seen on crutches at the end.
"I am gutted," said Blackett in the Coventry Telegraph. "It just doesn't look like a short-term injury. It was a gut-wrenching moment. You are sitting up there and you have just got to recompose everyone because of how much Joe means to everyone but it does not look good.
"I hope I am wrong. He is Wasps through and through. His leadership through the week, you have to see it to believe it. He has got this great aura about him and the ability to see any situation. There are not many people with the special leadership qualities he has."
Launchbury's injury aside, it was a morale-boosting result for Wasps, who won for only a third time in their last 12 fixtures, relying on two late tries to get over the line.
Bath's strong second-half rally had seen the West Country side take the lead with only eight minutes remaining before their replacement prop Beno Obano was sent off for a head-high challenge and that ultimately proved decisive.
Thomas Young scored two of Wasps' tries, with Josh Bassett, Michael Le Bourgeois and Paolo Odogwu recording the others, while Jacob Umaga added two penalties and four conversions.
Miles Reid, Josh McNally, Obano and Ben Spencer scored Bath's tries, with Orlando Bailey adding a penalty and three conversions.
Blackett said: "When they came back into in the second half, we became nervy and edgy as we lacked confidence but we showed a different mindset than recently to win it, especially when we went behind with 10 minutes to go.
"Last week we competed really well with Exeter for 50 minutes and I was really disappointed how we fell away after that.
"We played well in the first half but basic handling errors cost us as we should have been more than 10 points up at the interval."
Young fly-half Umaga deservedly earned the man of the match award by having a hand in a number of his side's tries and picking up a crucial 14 points with the boot.
Blackett said: "I thought Jacob was our best player at Exeter and he is starting to return to his best form."
Bath director of rugby Stuart Hooper was disappointed with his side's performance.
He said: "We didn't deliver today as we weren't accurate, especially in the first half, and you can't come away and expect to win on that basis.
"We got ourselves back into the game with a strong period in the second half by upping the tempo and there was a time when I thought we could sneak it but then came Beno's (Obano) red card, about which we can have no complaints.
"It is a missed chance to move up the Premiership table but as far as I'm aware a top-eight place will secure a Heineken Champions Cup spot for next season and we still have to play a number of sides above us so we can improve our position."
Next up for Bath is a European Challenge Cup semi-final at home to Montpellier.
Hooper said: "We'll keep fighting and that European game is a positive diversion for us after today's defeat."