The Premier League giants won just three of the eight games after they went top of the league table in the middle of January.
They have drawn four of their last six games and the dropped points mean that they have lost massive ground to league leaders Manchester City.
Manchester United are now firmly in the race to remain second and qualify for the Champions League next season.
But McIlroy feels that the story could have been different and he stressed that Manchester United had the squad to push for the league title this season.
However, he believes that if offered second spot at this stage of the season before the campaign started, Manchester United would have taken it.
The former Red Devil said on MUTV: “We are second in the league and if you said before the start of the season that at this stage of the season you are in second place, we would have taken it.
“But the way the games have gone, and this magnificent away run, we have just let ourselves down with too many draws.
“And it could have looked a bit different.
“I think we have got the strength and quality in the squad for me to push that little bit extra.”
Manchester United have not scored in their last two games with both of them being 0-0 draws.
