The arrival of De Gea also played a big role in the team's current achievements, to be honest if the goalkeeper was not him, maybe Fiorentina would have difficulty getting a top 4 position in the standings. Currently their biggest challenge is to maintain consistency because with the tight competition, experiencing just one defeat will threaten their position. In the next match Fiorentina will face Bologna, I think they can handle it.
De Gea's role with Fiorentina is quite noticeable, as evidenced by their ability to place them as one of the teams that currently has few goals conceded with 10 goals nested into their goal. Although we will not forget their overall defense role that can work well together so that they can get results like that.Facing Bologna, I can't say this is an easy match for them, because after all Bologna's appearance is not bad even though when compared to Fiorentina, Fiorentina can clearly show something better. However, it will be a difficult match for them to win the match.
But no jokes, there defense is good while Manchester City's offense has had some problems. Though a draw would be a result that both would accept, a defeat would be really bad as the table is becoming more tight towards the 27+ ranks. 
This is going to be a really tough one for Inter as a result. Inter are also really good in away games. They managed to beat Lazio away in their last head-to-head too. But I wouldn't still bet on a side here.
Both of them are very productive teams. Playing a big game might be assessed differently maybe but I think we won't watch a boring game.
