Leicester boss Richard Cockerill has confirmed that England internationals Manu Tuilagi and Louis Deacon both suffered hamstring injuries during Tigers' bonus point Aviva Premiership victory over Worcester at Sixways.
Centre Tuilagi and lock Deacon departed during the closing stages of a game Leicester won 32-13 that extended their unbeaten Premiership run to five matches.
"They have both got hamstring strains of various degrees," Cockerill said. "We are not sure to what extent at this stage. During the course of the 24 to 48 hours, we will know."
Cockerill added of the game: "It is not an easy place to come and play and get a result, so to win and get a bonus point is fantastic for us. I am delighted.
"We made a massive start (Leicester led 17-0 after 22 minutes), which was something we had talked about all week. A big start was important, and we got that.
"We've got Sale, who are another difficult side, on Sunday, then Wasps at home. We've got to keep trying to collect the points."
Worcester head Richard Hill said: "We showed a lack of urgency at the start. We were slow to react and we lacked a period of continuity.
"We had identified that Leicester don't play with too much width, so we knew we had to mark (Toby) Flood and the areas around him, but what did we do? We let him right through the middle.
"He had to be bottled up, but we didn't do that. We did not stick to our defensive strategy during the first 20 minutes, and those first 20 minutes killed us.
"Of all the games this season, that was one of our most disappointing. I am not happy with it. We under-performed, it is not good enough and we need a reaction."