United made it back-to-back 4-0 wins over Championship opponents in their defence of the FA Cup, with Marouane Fellaini, Chris Smalling, Henrikh Mkhitaryan and Bastian Schweinsteiger on target in a routine victory against Wigan Athletic at Old Trafford on Sunday.
This brings with it a heavy burden of fixture commitments and Mourinho was quick to draw a contrast between his own club and Liverpool, with Jurgen Klopp's men having only the title race to focus upon following a 2-1 cup loss at home to Wolves on Saturday.
"In a realistic way I think the Premier League is almost an impossible mission," he said.
"But I don't think about it I just think about the next match and that is not an impossible mission.
"In the EFL Cup we have 50 per cent chances of winning, in the FA Cup we are in the last 16 and in the Europa League we are still in the last 32, so there are plenty of matches to play.
"Liverpool will play 16 matches to the end of the season, and we are in this crazy situation. Southampton will have 15 days before the final.
"We will have two matches against Saint-Etienne [in the Europa League] and the fifth round of the FA Cup."
Mourinho has already voiced his displeasure over the second leg of United's EFL Cup semi-final at Hull City taking place on Thursday and he expects further quirks of the fixture calendar to hinder his own team and others.
"I can guess we will have some amazing gifts," he said. "Watford had to play today and they play Tuesday.
"It's a laugh. How can they play after two days with so many games yesterday?"