Robin van Persie is uncertain whether to remain at Manchester United and will consider his future in the summer. It is understood that the Dutchman has no release clause in a contract that will have two years left in July and the champions would resist any attempt by the player to leave.

The manner in which United resisted Wayne Rooney's desire to move to Chelsea last summer when he had become disgruntled with life at Old Trafford is now considered the default stance at the club when seeking to retain top-line players.

The approach with Rooney has proved a success, with the England striker committing fully to David Moyes' team. Last week he signed a five-and-a-half-year deal that keeps him at United until he is 33.

Following United's dismal 2-0 Champions League defeat at Oympiakos on Tuesday, Van Persie signalled his disquiet by complaining that his team-mates were taking up positions he wanted to occupy. Although the striker was careful to defend Moyes, his frustration with his fellow players was also an implied criticism of the manager's tactical approach.

In the opening last-16 first-leg defeat by the Greek championsVan Persie was starved of chances and squandered United's best opportunity towards the end of the match.

Van Persie was particularly disappointed when Sir Alex Ferguson, Moyes' predecessor, retired at the end of last season. Ferguson was a key factor in Van Persie agreeing to sign for United from Arsenal instead of Manchester City in 2012 in a £24m transfer, despite City having offered him a higher salary. As in his final campaign at the Emirates Van Persie had a virtually injury-free season last year and his goals were crucial to Ferguson claiming a 20th title for United. This term, however, Van Persie has been blighted by injuries and, with the summer's World Cup in Brazil potentially the 30-year-old's last, he is keen to be in prime condition for the tournament.

Moyes' position remains secure, with the manager retaining the full backing of the club's American owners, the Glazer family, despite the defeat by Olympiakos that leaves United's hopes of progressing to the quarter-finals hanging by a thread.

If Olympiakos, considered the weakest side in the last 16, are not defeated by three goals at Old Trafford in the return leg in three weeks' time, United will go out of the competition and would struggle to qualify for next season's tournament owing to their Premier league position.

In a season of disappointing results the manner of the defeat by Olympiakos at the Karaiskakis Stadium, in which United managed a single shot on target, proved a new low for the club.

Yet despite this – and a league position that has United 11 points from Liverpool in a Champions League berth – Moyes retains the full support of the club, though by the second leg, on 19 March, United could be even further behind in the Premier League.

Before playing hosts to Olympiakos, United travel to West Bromwich Albion on 8 March and then meet Liverpool at Old Trafford a week later.

The prospect of Champions League football next season is fading but the Old Trafford hierarchy are not unduly troubled about how this might impact on Moyes' drive to overhaul the squad in the close season.

The view is that elite players will still want to join the 20-times champions in the belief that United would miss only a single season of playing in the European Cup.