England paceman Simon Jones is on track to play in next week's fifth and final Ashes Test against Australia, according to team-mate Kevin Pietersen.
Jones is undergoing stints in an oxygen chamber to treat an ankle injury.
But Pietersen said on Friday he expected Jones to be ready in time for The Oval clash on 8 September.
"He is getting on very well. I spoke to him an hour ago and I think he will play," said the Hamsphire batsman. "He seems very confident and positive."
Jones has been a key figure in England's Ashes challenge this summer, with 18 wickets in the series at an average of 21.00 - better than any other frontline bowler.
England lead the series 2-1 and need to avoid defeat at The Oval to regain the Ashes for the first time since 1987.
Jones is visiting the London oxygen chamber twice a day to reduce the irritation around bone spurs in his right ankle.
"He is progressing pretty well at the moment," England bowling coach Troy Cooley told BBC Radio Five Live on Thursday.
"There is a chance, and if there is a chance I am sure Simon will take it."
Jones is likely to be named in the squad on Sunday and given every chance to prove his fitness before next Thursday.
"I'll get as much treatment as I can on it and touch wood - I'm touching my head - I'll be all right," he told BBC Sport.
Jones was only able to bowl four overs in the second innings of the fourth Test at Trent Bridge on Saturday, before pulling up with the problem.
And he had to watch from the balcony as his team-mates completed a thrilling three-wicket win.
"It was very painful, I was struggling to walk so there was no way I could have bowled," he said.
"I wanted to be out on the field with the boys. I felt pretty useless watching but there was nothing I could have done."
Hyperbaric oxygen chambers are used in the treatment of certain sports injuries because they can increase the oxygen supply to the injured part of the body.
While in the chamber, Jones will be breathing 100% oxygen, compared to the 21% oxygen and 79% nitrogen found in normal air.
Jones, who took 5-44 in Australia's first innings at Trent Bridge, is unsure whether he will need to have surgery on the troublesome ankle after the Ashes have finished.
"I'll just have to see what the specialists say," he added. "If I can get through the next game, we'll reassess from there."
Should Jones not return to fitness in time, England could struggle to find a suitable replacement, needing a draw at The Oval to win the Ashes for the first time in 18 years.
Hampshire's Chris Tremlett has been in the squad for all four Tests without getting a game, but it would be a gamble to bring him in for his debut with the Ashes at stake.
All-rounder Paul Collingwood is not as quick as Jones but could be drafted if runs are needed.
James Anderson has still not regained the form he produced when bursting onto the international scene three winters ago.
Somerset's Andy Caddick has produced match-winning performances in Test cricket but is now 36 and has not played for England since January 2003.