Manchester United last won the Champions League in 2008

Manchester United have a "realistic" chance of winning the Champions League by 2017, says manager Louis van Gaal.

Dutchman Van Gaal, 64, replaced David Moyes as manager on a three-year deal in 2014, and finished fourth in the Premier League last season.

United last won the Champions League in 2008, and lost in the final in 2009 and 2011.

"Reaching the final is also an aim and winning the final, you need a little bit of luck," said Van Gaal.

Van Gaal, who won the Champions League with Ajax in 1995 and came runner-up with Bayern Munich in 2010, added: "It is not only quality [but luck, too], and I think Manchester United knows and remembers that fantastically when they won the Champions League in 1999.

"When you reach the final, it is a fantastic but in the media it is nothing. For me as a manager, when you reach the final, you have done fantastically and to win the final, of course, all the honours are going to your team and yourself but I know better."

When asked if United can improve enough to win the Champions League by 2017, he said: "I hope so. That is realistic.

Asked for his reasons why, he replied: "Because I did it everywhere."

United progressing under Van Gaal

Morgan Schneiderlin (left), Bastian Schweinsteiger and Matteo Darmian all joined Man Utd this summer

Wednesday's game against Wolfsburg marks the return of Champions League football at Old Trafford after the Premier League leaders failed to qualify for last season's competition.

Under Scot Moyes, the side finished seventh and failed to qualify for the Champions League for the first time since the 1995-96 season.

The Red Devils have slowly made progress under former Barcelona and Bayern Munich boss Van Gaal, who has spent more than £200m on new signings since taking over.

After returning to Europe's elite club competition with a top-four finish in 2014-15, they have lost just once this campaign to go top of the league, one point ahead of rivals Manchester City.

United signings in 2015-16 Player Signed from Fee Anthony Martial Monaco £36m Memphis Depay PSV Eindhoven £31m Morgan Schneiderlin Southampton £25m Matteo Darmian Torino £12.7m Bastian Schweinsteiger Bayern Munich £6.3m Sergio Romero Sampdoria Free transfer

"We have made progressions in the maturity of the team and the balance of the team," said van Gaal. "We have improved when we compare with the team of last year.

"We have to improve to win the Premier League title or a tournament like the Champions League. We are still improving and I can see that every week."

Asked if could stay at the club beyond his current contract which ends in 2017, van Gaal replied: "Normally I shall leave after next year but what is normal in our football world?

"You never know so I cannot answer that question but I promised my wife to go with her to our paradise [villa in Portugal] so it shall be very hard for me to deny that promise.

"I was 55 and I go to Bayern Munich and next year I am 65 and say I stay a year longer, it shall be very hard to my wife."

'Wolfsburg a big challenge'

Louis van Gaal and Bastian Schweinsteiger were together in their time at Bayern Munich

Midfielder Bastian Schweinsteiger joined United from Bayern Munich in the summer, having won eight Bundesliga titles and one Champions League crown with the side.

The German feels "comfortable" at Old Trafford and says it is "an honour" to play for the side but has urged caution against opposition he is familiar with.

"I scored my first goal away in Wolfsburg so I have my good memories," said Schweinsteiger, 31.

"They are not easy to play against, they are always tough matches. They have a good team and in the last three of four years have improved a lot. It's a big challenge for us."