In an interview with The Sentinel, Geoff Thomas said: "We do feel optimistic about it, especially because my sister has found out she is a bone marrow match for me.
"There are more tests to undergo and we will know in around a fortnight if a transplant can go ahead.
"This really puts things into perspective - there are a lot more people walking around with worse problems than me, it's only because I was lucky enough to play football this has made the newspapers.
"Hopefully this can highlight the need for people to donate bone marrow to help other sufferers."
Former teammates paid tribute to the man who had two highly successful spells at Gresty Road and made nine England appearances.
Colin Little said: "He has always been a very, very fit guy and always in good shape. He is a brilliant bloke and everyone holds him in high regard.
"He's been used to fighting hard all his life to get what he did in the game and I'm sure he'll do the same with his illness."
Shaun Smith, the former Crewe Alex captain, said: "Like everyone I was deeply shocked to hear the news.
"All our thoughts are with him and the rest of his family. Knowing the type of guy he is he will fight whatever he has to fight head on."
Dave Slack, of Crewe Alex's Supporters' Associationalso paid trbute to the thirty-eight year old: "He has always been a favourite with fans and I would imagine all Crewe supporters would want to wish him well along with me.
"It's one of those things that you don't really expect leukaemia to affect sportsmen.
Once again, CreweAlex.com would like to wish the very speediest of recoveries to Geoff, we are all behind you.