De Gea, who arrived from Atletico Madrid in 2011, could face added competition if manager Ole Gunnar Solskjaer decides to bring back Dean Henderson following his successful loan spell at Sheffield United, but the Spain international has faith that he can keep the gloves.
"I trust in myself," De Gea said. "I showed my qualities all the years, so I just keep available for the manager.
"I'm always ready to play and try to help the team as always -- as I did always."
It was the third semifinal defeat of the season after disappointment in the last four of the Carabao Cup and the FA Cup and De Gea believes the squad needs more "experience" if they are to progress next season.
"I think we improved this season," he added. "We were 14 points behind the third position in the Premier League but we finished third at the end.
"We deserve to be in the final [of the Europa League], if we are honest. But maybe we need a bit of experience, more experience on the team, but we have to score the chances. I think we are playing very good football, attacking football.
"Let's keep improving, let's keep fighting for this club and let's try to win trophies next season."