Walter Zenga believes Inter will find it difficult to recover from their early-season turmoil and qualify for the Champions League.
Inter face arch rivals AC Milan in Serie A on Sunday having endured a tumultuous opening to the campaign, with Frank de Boer replacing Roberto Mancini as manager after the Italian was sacked in August, only for the Dutchman to be dismissed himself this month.
De Boer spent just 85 days in charge and the Inter players will now have to adapt to another new coach following the appointment of former Lazio boss Stefano Pioli.
Inter are eight points adrift of Milan, who sit in the third and final Champions League qualification spot, in ninth in the Serie A table and Zenga, who won Serie A and the UEFA Cup twice with the Nerazzurri, is under no illusions as to the size of the task facing Pioli.
"The Champions League? I'd say it's complicated," Zenga told Gazetta dello Sport.
"But of course Inter have a duty to try. As for the derby, there's never a real favourite, it's a game of unknowns and right now Inter are full of unknowns.
"The example would be this: I was in Wolverhampton [as Wolves manager] for 87 days, and in that time Inter had three coaches. It's not easy to recover from a blow like that.
"With 26 games to go, Inter have 17 points. Roma finished third with 80 last season. The calculation is simple."