Exeter Chiefs are still waiting to ascertain the full extent of an injury to winger Jack Nowell.
The 20-year-old England international damaged his shoulder in a collision with Logovii Mulipola during last weekend's Aviva Premiership defeat at Leicester.
"We're having some scans and some work done on his shoulder just to assess the damage," said Chiefs head coach Rob Baxter.
"Obviously we're hoping it's not too serious. Nothing particularly has shown up yet but it looks a doubt that he'll be fit for this weekend.
"We haven't found any muscle tears or whatever yet, but he has to have another set of scans to assess fully what's going on around his shoulder and neck.
"We've got a week off next week, and by the time we get to the end of next week we'll know exactly where we are with him."
Nowell made his England debut in the Six Nations loss to France and then started all four of their reamining matches in the tournament.
Exeter face Gloucester at Sandy Park in league action this weekend.