Former Fiorentina goalkeeper Alex Manninger admits he has seen David de Gea struggling this season.
De Gea is in his second season with the Viola, but has battled to reach the heights of last term.
Manninger told Radio FirenzeViola: "That's because the team is different from last year. Last year, he joined a Fiorentina side that was hungry and had a positive season, thanks in part to his experience.
"It was a good idea to sign him, but time doesn't stand still; he's his age and has a lot of games under his belt. When you work with a team that's perhaps a little younger and in a period of change, you can feel it, but De Gea's quality remains and he can be a huge help. But the whole team is needed, not just him."
On Fiorentina's slow start under coach Stefano Pioli, he added: "It's a surprise for me. I was in Florence two years ago when Viola Park was built. I visited the training center: it was truly spectacular.
"I thought that could have been the start of the Viola's climb towards the top five in Italy. But so far they've disappointed, and despite the way some results have come about, the standings ultimately tell the truth."