Jose Mourinho's fears that a gruelling schedule could prove problematic for Manchester United were confirmed in a drab 0-0 draw against West Bromwich Albion on Saturday.
The first of nine fixtures to come in April ended with United having to settle for a draw at Old Trafford for the eighth time in the Premier League this season.
Without six key players due to injury and suspension, it was a sign that United's taxing campaign may finally be catching up with them as they attempt to secure a place in next season's Champions League.
United remain fifth, four points behind fourth placed Manchester City, who face Arsenal on Sunday.
United's first half domination was near total although, for all their possession, the home side failed to force goalkeeper Ben Foster into a noteworthy save.
Anthony Martial came closest to a breakthrough, just before the half hour, when he rose powerfully at the far post to meet a Jesse Lingard cross with a strong header that flew over the cross-bar.
But, with Albion often packing all 11 players well inside their own half, United lacked the inspiration to break down Tony Pulis' disciplined side.
It might have been a different story had Lingard succeeded with a ninth minute shot that flew over after a committed run by Martial saw the ball deflected to him.
And Martial also came close on 19 minutes after Michael Carrick sparked another wave of attacks by squaring to Lingard who moved the ball to his French team mate for a shot which curled just wide.
Eric Bailly also almost capitalised after Hal Robson-Kanu stumbled as he attempted to clear a Henrikh Mkhitaryan corner and, as the club's record goalscorer Wayne Rooney watched from the United bench, Mourinho's side struggled to break the deadlock.
- Frustrations -
As the half-time whistle blew, Carrick and Martial protested loudly to referee Mike Dean, the latter pointing to a lump on his face that appeared to be the result of a challenge in the final minute from West Brom's Craig Dawson.
Dean waved the players away and took no action, however, as United supporters echoed their players' frustrations by booing the referee off the pitch.
There was a first moment of genuine concern for United on 51 minutes.
Dawson's run to the right-hand by-line ended with the defender pulling the ball back for former United midfielder Darren Fletcher whose shot was charged down by Bailly.
United responded quickly, with Martial setting up Mkhitaryan who was crowded out only for the ball to break kindly to Marouane Fellaini who threaded a shot through a crowded area but wide of the goal.
The game was finally opening up and Fellaini's pass set up Martial for a low 25-yard shot which missed the right-hand post by inches.
A rare Albion error, from a misplaced pass from Gareth McAuley, let in Mkhitaryan but his attempt to chip over Foster lacked power and the keeper was able to reach out and save.
And Foster was again called into action, this time from a ferocious 25-yard shot from Rashford which forced the Albion number one into an impressive and acrobatic flying save.
By now, United supporters had long been calling for the introduction of Rooney and received their wish on 74 minutes when he was brought on to replace Mkhitaryan.
But Rooney made little impact as, Rashford, again from long range, sent a low shot just wide and then the youngster forced Foster into a magnificent save from a 25-yard free-kick.
In between, there was one more moment of anxiety for United as Fletcher's long-range shot was fumbled by De Gea who was relieved to see the ball strike the bar and rebound to safety.