City are putting forward their appeal to the Court of Arbitration for Sport (Cas) next week in an effort to overturn a two-year ban handed down by Uefa in February for alleged breaches of financial fair play (FFP) rules.
If their appeal fails, Pep Guardiola’s team will not be able to compete in the Champions League, and Martinez believes such a scenario would push the 28-year-old De Bruyne to weigh up where he wants to spend his peak years as one of the world’s leading midfield players.
“Kevin is a winner,” Martinez told beIN Sports. “I think he will weigh up everything before his decision. He will take into consideration if there is a ban in the Champions League, if the coach that he has a fantastic relationship is going to stay at the club.
“As you can imagine, this is the moment that a player like Kevin De Bruyne is enjoying his best years and he’s given them to Manchester City. But then you think, ‘what’s going to happen in the next four, five years?’ Nobody can give him good advice, the only advice is the one that you feel as a player.
“The last thing you can afford to do is finish your career and say ‘I should have moved in that moment, or I should have stayed’. Kevin is very mature and will take everything into consideration. Of course, if Man City have a ban he will take that into his decision making.
“Over the years he’s shown that if he’s happy somewhere he likes to stay and win things. I think it’s going to have a major say what happens at the club if there is a ban – what’s going to happen with the manager and what’s going to happen with [any] future project?”
City’s appeal will be put to Cas on Monday, starting a hearing process which is expected to last three days.