United crashed out of Europe's top club competition with a 4-2 aggregate defeat to Bayern Munich on Wednesday night.
Given that United are seven points adrift of the top four with five matches left, their chances of qualifying for next season's tournament through the Premier League are very slim.
But Moyes is confident that the lure of playing for such a historically successful club will be enough to persuade the top players to come to Old Trafford during this summer's much-needed re-building exercise.
"My focus is on getting a side together to get back in the Champions League," the United manager said.
"We're looking to spend the right money on players who are available and it's not anything to do with Champions League.
"Any players we've quietly discussed it with are more than happy to join Manchester United. They know it's not a long-term thing."
The need for reinforcements in defence became clear at the Allianz Arena when United conceded less than a minute after taking the lead through Patrice Evra's stunning finish.
"It's the sort of thing you learn as a schoolboy -once you score a goal, make sure you don't concede," the Scot said.
"You get into position and do your job. We had concentrated so fabulously well throughout the game.
"The players had done tactically well. Their positioning was good and they did their jobs.
"For us just to give it up on that moment, the goal up, was really disappointing."
Moyes' task was not helped by two glaring misses from Wayne Rooney, who played with a pain-killing injection in his injured toe.
Moyes defended his decision to select the player even though his injury was clearly inhibiting him.
"I thought at times he was having a struggle striking the ball on some occasions," the Scot said.
"I was concerned that he hadn't trained all week and he had taken an injection.
"But he is so vital a player to us, especially with Robin van Persie out (injured).
"But he just had a couple of opportunities and he couldn't quite take them."
Mario Mandzukic's equaliser triggered a collapse that saw Bayern come away with a 3-1 win on the night.
Thomas Muller and Arjen Robben found the net to seal the win after what was often a difficult night for Pep Guardiola's team due to the opposition's negative tactics.
"I knew it would be hard," he said.
"It's not easy to play against a team when they have eight players in their box. It happened in Manchester too.
"We decided to create a bit more passing in midfield and get the ball wide. They defended well, but when it got to 1-1 we played much better and we deserve to be in the semi-finals."
Bayern will find out whether they draw Chelsea, Atletico Madrid or Real Madrid on Friday.