Quinton Fortune will forego his summer holidays to prove he is fit enough for a move to Celtic.
The South Africa midfielder was released by Manchester United after failing to hold down a regular first-team place at Old Trafford following a knee injury.
After receiving an invite from ex-United team-mate Roy Keane, the 29-year-old visited Glasgow on Friday for an informal chat with Celtic manager Gordon Strachan.
Fortune is awaiting a call from Peter Lawwell next week when the Hoops' chief executive returns from South Korea.
The South African's agent Francis Martin told the Daily Record: 'There is no doubt that Celtic are very high on the list of Quinton's list of options.
'He was hugely impressed by the set-up and very encouraged that Gordon Strachan was so keen to meet him before Gordon went on holiday.
'Fitness will not be an issue and neither will be motivation.
'Quinton is desperate to play top-class football again after missing most of the season.
'He is fitter than ever and is so determined to do well that he is not going on holiday this summer.
'He has started pre-season training on his own.'