The selection of midfielder Joe Ledley will be manager Chris Coleman’s biggest decision as he names Wales’ final 23-man squad for Euro 2016 on Tuesday.
Ledley, 29. has resumed light training after breaking his leg on 7 May.
Wales begin their campaign against Slovakia on 11 June, before facing England five days later.
“If Joe could guarantee he could be fit to face England, I would take the gamble,” former Wales striker Iwan Roberts told BBC Radio Wales Sport.
“If he was to say ‘no, but I’ve got a 75% chance of being fit for the last game against Russia’, I think Chris [Coleman] has got a massive decision to make.”
Crystal Palace midfielder Ledley missed his side’s FA Cup final defeat to Manchester United earlier this month.
Coleman will name his 23-man squad from an extended group of 29 players he took to a training camp in Portugal earlier this month.
The former Fulham and Real Sociedad manager has said he will give Ledley until the last minute to prove his fitness.
Walsall striker Tom Bradshaw and Blackburn defender Adam Henley are the only two players from Wales’ training squad to have been ruled out of contention for Euro 2016 because of injury.
Forward Gareth Bale will rejoin the Wales squad having missed the training camp as he helped Real Madrid win the Champions League on Saturday.