Jose Mourinho has told MUTV that Manchester United fans could have done more to lift his tired players during Sunday's 1-1 draw with Swansea at Old Trafford.
United were held to their 10th home league draw of the season by the relegation-threatened Swans in what was their 57th game of the season compared to the 38 played by their opponents.
Mourinho said afterwards that his team were feeling the effects of a long campaign that could extend to 64 games if they reach the Europa League final.
But he questioned whether the United supporters at Old Trafford on Sunday realised how much the players were struggling.
"Did the supporters know it?" Mourinho said. "Because if they know it, and they think about it, they would be more supportive of the players who give everything, deserve everything and are at their limits.
"The team is in trouble, the boys are in trouble. But when you give everything I cannot demand more. I'm not happy with the result. I'm very happy with the boys."
United head to Spain this week for their Europa League semifinal first leg against Celta Vigo on Thursday.
And Mourinho will have to contend with a growing injury list after Luke Shaw and Eric Bailly both limped off with problems.
It means United could be without seven first team players including Zlatan Ibrahimovic, Marcos Rojo, Chris Smalling, Phil Jones and Timothy Fosu-Mensah at the Estadio Municipal de Balaidos on Thursday.
Mourinho said United had fallen victim to a fixture list that has "punished" his players and hinted he might play reserves against Crystal Palace on the final day of the season.
"It's a consequence of our success but it's also a consequence of the calendar," he told a news conference on Sunday.
"You cannot be punished because we play the League Cup final, you play the final and then you have to play a game in midweek. Why don't you stop the competition [the Premier League] when you play the final?
"You are punished for doing well and if we beat Celta, we have the final -- in this moment that is obviously hypothetical -- but the Europa League final is on the Wednesday and then we play against Crystal Palace on the Sunday.
"We play Southampton away two days before the final. So they want us to play the final, and we would be playing in disaster consequences.
"So again maybe this result is also a blessing, because maybe I can bring [under-23s manager] Nicky Butt and his team to play against Crystal Palace."