Timo Werner has told Sky Sports he is still not convinced about joining Liverpool, Manchester City or United over staying at RB Leipzig.
The 24-year-old Germany striker, who was also once a target for Tottenham, is widely reported to be high on the lists at a string of top clubs across Europe this summer.
But Werner admits he has a decision to make about whether to compete with other top players for a place in a team or continue at Leipzig, who are now competing for the Bundesliga title and progressing in the Champions League.
Ahead of their second-leg clash with Spurs, which they lead 1-0, he said: "At this time in professional soccer there are two different variations. The first is to be part of a team like Liverpool or Manchester City. They have a good working team. The teams have also great coaches.
"But this is the question: do you want to go to that kind of team, because the situation is already that hard for each member and you want to be a part of it? That's one point you have to look at.
"The other side are teams which need some big changes, because they just won a few big titles, but they are not able to compete on the highest level anymore. For me Manchester United is one of these teams.
"So at this point of my career I'm asking myself: do I want to be part of a new team, to build up something new, or do I want to stay at my team and make something great?"
Werner, who has scored 21 goals in 25 Bundesliga appearances this season, has previously spoken of his pride at being linked with Liverpool, and boss Jurgen Klopp has also made positive noises about the 24-year-old.