The Toffees failed to return to winning ways in the Premier League, as they went down 1-0 to United away from home on Sunday evening.
Anthony Martial’s goal nine minutes into the second half proved to be the difference between the two sides at Old Trafford.
Deulofeu, who started the match and played for 63 minutes, has taken to Twitter to express his disappointment at the final result.
The defeat against United means that Everton are now 12th in the Premier League table with 38 points from 30 matches.
Although Roberto Martinez’s side have a game in hand, there is a distinct possibility that they could end the season in the bottom half of the league table.
It seems that the only way Everton can salvage their 2015-16 campaign is by winning the FA Cup.