The 31-year-old scored in the 2-0 win over Burnley last Sunday, his 251st goal for the club and his first since January as he played a full 90 minutes in a Premier League game for the first time since September.
Rooney was partnered with Anthony Martial against the Clarets, coming back into the team because of a knee ligament injury to Zlatan Ibrahimovic and manager Jose Mourinho's decision to rest Marcus Rashford ahead of the Manchester derby.
Rooney has made just 10 Premier League starts this season and in February issued a statement saying he was committed to the Old Trafford club despite speculation over a possible move to the Chinese Super League or boyhood club Everton in the summer.
Rooney, whose chances this season have also been limited by an ankle problem, said when asked about speculation over his future: "I think I answered that question in February.
"My focus at the minute is to help us try and reach the Europa League final and hopefully win it and to try and make sure we finish in the top four. That's my aim, that's my focus at the minute and that's what I'll do until the end of the season."
Rooney added in an interview broadcast on Sky Sports News: "I think that [the speculation] has happened over the last few years. All I can do is keep working, keep trying to - not prove myself, but prove people wrong.
Read the full article on eurosport.co.uk: Rooney focused on helping United to Europa League glory and top-four finish