Louis van Gaal refused to use the attack on Manchester United's bus as an excuse for his side's 3-2 defeat to West Ham on Tuesday.
Kick-off was delayed by 45 minutes after United's arrival at the stadium was halted by West Ham fans attacking the team bus.
United were given the time back in full to prepare for the game but started sluggishly as Diafra Sakho opened the scoring just 10 minutes into proceedings.
Andy Carroll and Dimitri Payet both had good chances to add to the lead as United struggled to come to terms with the pace of the game but eventually hit the lead through an Anthony Martial double, only for goals from Michail Antonio and Winston Reid to seal the win for West Ham in what was Upton Park's last game.
But while Van Gaal said some of United's players may have been affected by what happened prior to kick-off, he refused to use it as an excuse as the team's Champions League hopes were dealt a major blow.
"We live in this world. We know that. I know that, it is not the first time it happens, but okay, I have a long experience in football, there are players that don't have the experience, so it shall have an influence," he said.
"But I don't think we should look for excuses. We changed the match in the second-half, 20 minutes before time, we are ahead, so I don't think you have to look for that excuse."
The Dutchman also declined to criticise those involved.
"I don't think that I have to say that because I think the media has filmed it so you can see it by your own eyes, you can make your opinion by yourself because I think the images shall be very clear," Van Gaal added.
The loss left fifth-placed United needing to beat AFC Bournemouth on Sunday, while hoping Manchester City lose against Swansea City if they are to qualify for next season's Champions League.