Exeter Chiefs coach Ali Hepher says prop Hoani Tui could be fit for Saturday's match at Northampton.
The 27-year-old came off with a calf injury in the Chiefs' win over Wasps.
"We're still monitoring it, it's still going day-by-day for Hoani and hopefully he can come through," Hepher told BBC Radio Devon.
"But equally if he doesn't, John Andress stepped in fantastically well at the weekend and I'm sure he will again if he's needed."
With Craig Mitchell at the World Cup with Wales and Chris Budgen away with the army, the Chiefs were forced to bring in Cornish Pirates prop Alan Paver on loan.
Paver was injured against Saracens last week but Hepher says the Chiefs are working hard to get players fit.
"We've done a lot of work in the physio room, they're working hard and the guys have come through well," he said.
"It's unfortunate for Alan, it's real shame.
"The Cornish Pirates helped us out by loaning him and he came up and did fantastically well for us and it's just a shame that he pulled up with a calf injury because he was going exceptionally well."