Jose Mourinho is confident David De Gea will sign a new and improved deal at Manchester United after again proving himself to be the “best goalkeeper in the world”.

United reached the Champions League last-16 with a game to spare on Tuesday, having edged past Young Boys 1-0 thanks to Marouane Fellaini’s last-gasp strike.

Mourinho’s relief was clear as he threw water bottles on to the floor and the manager thanked goalkeeper De Gea for saving their blushes as much as Fellaini, having superbly clawed a deflected Ulisses Garcia effort off the line in the 70th minute.

The Young Boys substitute had even turned to celebrate, before realising De Gea had somehow stopped it.

The United boss is confident the Spaniard will sign a new deal, with his current contract up in 2020 once the one-year extension clause is activated.

“He is a world-class player,” Mourinho said.

“He is the best goalkeeper in the world and, if our ambitions are to be a big club, to be a winning club, you need the best goalkeeper in the world – and you need also some other players the best in the world.

“In this case, we have the best goalkeeper in the world and I know that he wants to stay.

“I know that his agent is happy to do what the player wants and I also know that the board wants him to stay and they’re working on that, so hopefully sooner or later they arrive into good conclusions.”