Roberto Di Matteo says ex-captain Stiliyan Petrov has been doing 'very well' at Villa's pre-season training camp in Austria.
The 37-year-old midfielder, who was diagnosed with acute leukaemia four years ago, featured in the 8-0 friendly win over GAK Graz on Saturday and is bidding to win a deal for the upcoming season in the Championship.
Di Matteo, who will soon decide on whether there is a role for the Bulgarian, said: "Stiliyan is an example of willingness and bravery to everybody that is here.
"He has come into pre-season and not missed one minute. You can see how hard he is working in training. It's a remarkable journey for him. I have already told him that he is really an example for all of us."
Meanwhile, four of Villa's Championship fixtures have been moved – three for TV.
The trip to Derby on August 20 will now kick off at 5.30pm, and the home meeting with Nottingham Forest has been moved to Sunday, September 11 (1.15pm).
As a result of the Forest fixture being rescheduled, the game at home to Brentford moves to Wednesday, September 14 (7.45pm), while the third game selected for TV is the home match against Newcastle, which will now kick off at 5.30pm on Saturday, September 24.