Bath and England centre Matt Banahan is to have a scan on his knee after being forced off during the West Country club's 30-23 win over Wasps.
The giant three-quarter limped off during the closing stages as Bath made it two wins from two at the start of the new season, punishing Wasps for a series of costly errors.
Banahan left the Rec in a leg brace, and Bath skills coach Brad Davis admits it will be a waiting game to determine the severity of the problem.
"Matt has damaged his knee and we will know more about it in the next 48 hours," he said. "He will go to have a scan and we will wait and see what the results are, but he has been put in a brace."
Head coach Toby Booth added: "All injuries are a worry. The people who are near the top of the table at the end of the season are the sides whose players stay fit and healthy, giving them more firepower at their disposal.
"We have a few dents in the squad already but we will have Sam Vesty, Stephen Donald and Tom Heathcote to come back soon."
Banahan had run in Bath's first try during the opening period , which was followed up by scores from wings Tom Biggs and Kyle Eastmond after the break.
Eastmond whose try was his first since joining the club from St Helens put in a particularly eye-catching performance.
"He is a smart player," said Davis. "We knew that when we signed him. His ability has never been in doubt and the try he scored was a contender for try of the season.
"Apart from that he has a lot about his game in terms of passing, kicking and running. He is one of the best at the club and we are very pleased with his development."
Wasps boss Dai Young was unimpressed by his side's performance, which was characterised by missed tackles and a loose pass that cost the Londoners dear.
"We looked dangerous in open play and that was it," he said. "We had no patience with the ball and we offloaded when it was not on.
"Whenever the game got loose we looked dangerous but we never looked like constructing anything ourselves and Bath did the basics better than us.
"They had a good scrum and driving line-out and they did what was needed."