David Wilson does not expect to make it past the hour mark when he lines up for England against Ireland on Saturday.
An injury to Dan Cole has pressed the Bath prop into Six Nations action on the back of just 47 minutes' playing time since he damaged a calf muscle two months ago.
To add to a tough assignment, Wilson will be up against Lions loosehead Cian Healy as the Irish come to Twickenham with the Grand Slam still a possibility.
Henry Thomas will be waiting on the bench when Wilson's body tells him enough is enough, and that moment could come shortly after half-time.
"I think I'm ready to play on Saturday," Wilson said. "I would have liked one more game to get my match fitness up, but that's the way it goes.
"I've got no idea how long I can play for. As long as possible I guess - that's what I'm aiming for. I want to do as well as I can for as long as I can.
"Maybe 50 or 60 minutes. If I get through that and perform well, I'll be reasonably happy. I'm obviously eager to make a big impact."
Wilson struggled at times on his club return against Exeter last weekend, but he expects to be in better shape for the experience come Saturday.
"I was well tested in the scrum by Exeter," he said. "It was a fast game and the pitch was heavy.
"It was a good workover and I am happy about that. It was a tough test. It might have looked hard and it was. I worked pretty hard last week so feel I will be 20-30% better this week.
"I'm aiming to do the basics well - scrum well, line-out well, get through that, go for as long as I can and not let anyone down."