Louis van Gaal accepted Manchester United were not at their best against Everton but was pleased to keep up the pressure for top four places.
Anthony Martial scored the only goal as Van Gaal's United side edged out the Toffees 1-0 at Old Trafford on Sunday to move back within a point of fourth-placed Manchester City in the Barclays Premier League.
Van Gaal said: "Today was not our best form because I think we were not fresh enough, and we had more or less three days preparation - much more than against City or Arsenal.
"You never know as a manager how players are coming back from the international break. We gave them one day more off than usual but we started not fresh. Everton were much fresher and you could see that in the pitch.
"I have said in the dressing room that it was very important to win today otherwise the victory against City was worthless.
"We keep in touch with City, one point behind, and we keep in touch with Arsenal, five points behind. We have to play Tottenham, not an easy match, but normally we play very well against the top teams and if we continue like that I am very happy."
United's 54th-minute goal was set up by full-back Tim Fosu-Mensah, who had come off the bench to replace the ineffective Marcos Rojo. The Argentinian endured a torrid time in the first half, particularly when up against Gerard Deulofeu and Van Gaal thought he was feeling the effects of international duty.
Van Gaal said: "I think Rojo had a problem with his jet lag, so I changed him. I saw the space on the right side and I said to Timothy that, 'You have to take profit of that'.
"When a player does that it is a bit of luck for the manager but every credit is for Timothy, not the manager."
Everton matched United in most departments but defeat strengthened the sense of under-achievement that has enveloped their Premier League campaign.
The Merseysiders remain 12th in the table and were booed off by their own fans at the final whistle.
Manager Roberto Martinez said: "We all are (booing). I think you could hear our boos in the dressing room. It is exactly the same.
"We are a club that there has been a bit of a change of generation. A lot of players have come in but incredible young talent needs know-how and lessons and to develop.
"The frustration we all have is we can see the quality we have in our squad and we can't really gain some sort of momenutm.
"But 1984 is the last time we got into the semi-finals of the two domestic cups and this generation can make us very successful."
Martinez was disappointed his side could not build on a positive start to the game.
The Spaniard said: "We adapted to the game really well and maybe we shocked Man Utd a little bit. They never seemed to feel comfortable.
"The first half was probably exactly what we were looking for. You look at the little amount Joel Robles was involved for - that is the first time I have seen such a controlling 45 minutes.
"But we didn't use opportunities of great one-on-ones well enough. In the second half we got into a comfortable mood but we switched off in one action which is an unfortunate, easy goal to concede.
"That moment was a massive blow. You don't expect to concede when you are well in the game."