Manchester United goalkeeper David De Gea says his team must improve "in a number of areas" if they are to overtake Manchester City next season.
United's neighbours cantered to the Premier League title this term, having clinched the trophy last month.
"Next season is a new season and we have to improve in a number of areas," he told Sky Sports.
"We have to fight to be involved at the end of the season.
"It is not just Manchester City we will be challenging next season, five or six teams fight for the Premier League. It is a case of hard work to be in there at the wire."