The United manager said: “He can play the final, that is a goal that he has to live for.
“In my opinion it is not impossible. It gives him the spirit [to come back].”
While United’s immediate target in Europe is the Europa League, they are still chasing a top-four finish in the Premier League to guarantee Champions League football next season.
And Van Gaal believes they could even mount a title challenge if his side - 10 points leaders Leicester and five adrift of fourth-placed Arsenal - win at Chelsea on Sunday after back-to-back victories against Derby in the FA Cup and Stoke.
He added: “We don’t have to exaggerate but I have the feeling if we shall beat Chelsea, although that is very difficult because under Guus Hiddink they don’t lose, then I think our league is starting again.
“Michael Carrick said to me and I have the same feeling, the competition is not yet finished, not for Manchester United or the other teams.
Interactive: 0602 Chelsea v Man Utd postions
“We have the feeling, and that's because we are winning twice in a row with sparkling football, with goals, clean sheets, against opponents who were in great form after Stoke City played Liverpool off the pitch in the Capital One Cup but then lost on penalties.
“I have said always that only Crystal Palace and Arsenal this season were better than Manchester United this season.”
- Telegraph