Spanish goalkeeper Diego Lopez said he would keep the faith despite being sidelined by teenager Gianluigi Donnarumma for a 2-1 win over Sassuolo that ended the Rossoneri's three-game winless streak on Sunday.

Former Villarreal and Real Madrid 'keeper Lopez had been under fire for a series of under-par displays for the struggling Serie A giants.

But despite counter-claims he remains one of Milan's few strong points amid yet another difficult start to the season, he was replaced by Donnarumma -- aged 16 years and 242 days -- for Sunday's game at the San Siro.

Donnarumma conceded his first league goal in Italy's top flight when Sassuolo striker Domenico Berardi wrong-footed him with a free kick that crept over the defensive wall shortly after the restart.

But the towering teenager kept the damage to a minimum as Milan ended their recent struggles with goals from Carlos Bacca, from the penalty spot, and Luiz Adriano in the 86th minute.

Reports earlier claimed Lopez could quit the club in January if he was replaced by Donnarumma.

The Spaniard told Rai after the game he considered Donnarumma "the future of Milan and of Italian football", but it was clear in a later interview with Sky Sport he had not fully digested coach Sinisa Mihajlovic's decision.

"I'm calm, I have plenty of belief in my performances. I've been here a year and half and played nearly 40 games with Milan and the outcome is pretty positive," said Lopez.

"I've always sought to be a leader of this team. I respect the coach's wishes, just as I respect this great club."

Milan coach Mihajlovic played down suggestions of a rift, saying after the game: "I haven't rejected Lopez. He's a top 'keeper that I have a lot of respect for but he hasn't played well recently, the same as some defenders, midfielders and forwards.

"I decided to give Gigi his chance because I don't look at a player's age, only how well he's playing. It was my choice and I take responsibility."

Club CEO Adriano Galliani, meanwhile, told Milan Channel: "Lopez has our full backing. I understand why he might feel a little bitter, but he has to respect the coach's wishes.

"A goalkeeper is a player like any other."

Milan's fourth win of the season moved them up to provisional 10th place and seven points behind new leaders Roma following their 2-1 win at Fiorentina.

Mihajlovic, who held crisis talks with club owner Silvio Berlusconi two weeks ago, is not out of the woods yet as thousands of fans protested the club's ongoing woes by staying away from the stadium.

The Serbian added: "It was a peaceful protest, and I want to thank the fans who have stood by us in this period.

"It was an important win for us, we left ourselves exposed far less than in previous games and we created a lot of chances.

"Hats off to the lads because we fully deserved the win."