The seven-times world champion, who won five of his titles with Ferrari before retiring in 2006, has struggled to be competitive in his comeback with Mercedes GP.
Now 42, the German has yet to stand on a podium since returning to F1 last season and has faced constant criticism that he is too old to be competitive.
"I would say that Michael, knowing him quite well, he has not changed his approach in the way that he is doing his job now," Domenicali said at Monza ahead of this weekend's Italian Grand Prix.
Schumacher is a six-times winner at Monza, with five of those victories coming with Ferrari.
"Honestly, I can see him fighting for something important if he has a great car.
"The difference from the past is that we were used to having only two drivers that were fighting. Now in this period we have four or five drivers that really, if you give them the same car, can challenge to be the winner."
Red Bull's world champion Sebastian Vettel has won seven of 12 races so far this season but both McLaren drivers Lewis Hamilton and Jenson Button have won twice each while Ferrari's Fernando Alonso won the British Grand Prix at Silverstone.
Schumacher's best result to date this year has been fourth place in Canada.
"Knowing him, the more you criticise him, the more he will want to show to everyone that he doesn't deserve that," said Domenicali.
"I think that if he has the chance to have a great car, I'm sure that he will show once again (what he can do).
"Seven world titles mean something. I think that to win another title is difficult considering the conditions around but to show that he is still a top driver, I think that he will be there."