Louis van Gaal says Manchester United are not good enough to win the Champions League.
United face Wolfsburg in Germany on Tuesday in their final Champions League group match, needing a victory to be sure of earning qualification to the last-16.
But ahead of the game at the Volkswagen Arena, Van Gaal conceded that United's chances of lifting European football's biggest prize for a fourth time in their history are slim.
"I don't think that we are able to win the Champions League now. Maybe next year when we strengthen our selection again," Van Gaal said.
"But now we have to come as much as possible and maybe we can beat everyone, that I am sure. And we have proven that already, also in the Premier League.
"But normally we are not good enough to win the Champions League. You can win, and when we are there we shall try to do everything but you also have to be realistic.
"I'm happy with my squad now but we can strengthen the selection still in [certain] positions, for example the left-back position is not so [well] covered."
United were held to a 0-0 draw by West Ham in the Premier League on Saturday - their sixth goalless draw of the season.
Van Gaal's were booed off at the final whistle by sections of the home support after missing the chance to move within a point of current league leaders Leicester City.
The 64-year-old has drawn 13.2 per cent of his Premier League games in charge of United 0-0 - the highest percentage of any manager in the club's history.
Sky sources understand United are already planning for life after Van Gaal.
The Dutchman's contract at Old Trafford runs until 2017 and United fully expect him to see out that deal.
United are also not ruling out Ryan Giggs, Gary Neville or current Bayern Munich manager Pep Guardiola taking over in 18 months time when Van Gaal's tenure is set to end.
Sky sources also understand United will be heavily active in the transfer market next summer, but will not be drawn into spending big money in the upcoming January transfer window.