Wasps boss Dai Young was concerned about Joe Launchbury after the England lock was taken off in a dazed condition during the victory over Worcester.
Launchbury suffered two knocks to the head in the 32-22 Aviva Premiership triumph at the Ricoh Arena and will give England coach Eddie Jones some cause for concern ahead of his forthcoming squad announcement.
Young said: "He's taken a nasty head knock but he's up and about. He's talking and appears to be fine but will have to go through the relevant protocols.
"It could take one or six weeks, it's impossible to tell at this stage."
The afternoon could have been a whole lot worse for the home side as faultless kicking from Andy Symonds had threatened to earn Warriors a shock win. He kicked five penalties and converted an interception try from Cooper Vuna.
Lethargic Wasps trailed 22-13 with 12 minutes to go but tries from replacement Guy Thompson, and Frank Halai and Sailosi Tagicakibau, broke Worcester's hearts and sent them back to Sixways without even a bonus point.
Kearnan Myall had scored Wasps' first try with Jimmy Gopperth converting three of the tries and adding two penalties.
Young said: "We got out of jail as, with eight minutes to go, a betting man would have clearly put money on them.
"I'm frustrated with our lack of accuracy as we had lots of possession but we didn't create enough and I'm pleased we didn't give up.
"I still expect to see Launchbury, Elliot Daly, Joe Simpson, Matt Mullan and James Haskell selected in the England squad."
That will be announced on Wednesday with Wasps skipper Haskell confirming he is keen to be included.
"I want to play for England, it's the reason I get up in the morning and put my body through hell," he said.
"I haven't heard anything from the coach but I believe my form is good.
"We made life difficult for ourselves today as we weren't ruthless enough. It was nerve-racking but I had faith in the boys."
Worcester boss Dean Ryan was again frustrated by his side's failure to close out the game.
He said: "We still haven't got the experience to get us over the line. At the end our kicking game wasn't accurate enough.
"They got more and more frustrated as we had a limited game plan and we came very close. We were stripped of a number of players and had to play a third choice fly-half so we kept it simple but it was another opportunity missed."