Martial has netted five goals in his last five games and is another player who is said to be looking for some kind of parity with Sanchez, who he is outperforming this season.
Mourinho's men looked all set to pick up the crucial three points only for Ross Barkley to spoil the party with a goal in the 96th minute.
As Mourinho admitted afterwards, "At half time I thought I was the luckiest manager in the Premier League to be 1-1 when it could've been 5 or 6-2".
Ahead of Saturday's trip to Bournemouth, which ended 2-1 to United, Mourinho urged Martial to stay at the Theatre of Dreams.
But the Portuguese manager conceded that his side were defensively bad in the first 45 minutes of the match and had a better second half in the match.
The Chile worldwide started with objective as he looked to impress but ended up taking a seat within the first few minutes when he cleared the advertising hoarding and ended up on a home fan's lap.
Speaking of good attacking form, Callum Wilson has been huge for Bournemouth this year. "We created a lot of chances, we pressed higher, we had much more aggression, intensity and intention".
But the manager believes his team have been hindered by a series of hard back-to-back away fixtures, citing the fact they must travel to Manchester City in the Premier League on November 11, four days after a Champions League trip to Juventus, and that they visit Liverpool in December after a European away game against Valencia. "We don't know, a muscle problem, and we have to wait a little bit". "Hopefully they can turn their form around, win a few more games and keep the pressure on the top of the table and get back up there, which is where we all want to see them".
"I can't understand", he added.
The Red Devils fell behind again with Callum Wilson netting in the 11th minute after Ryan Fraser had earlier wasted a fine goalscoring opportunity.