Schlupp, who can play on the left flank or as a striker, has spent the last four weeks on trial with the Red Devils' Under-21 side, having been touted as a possible star of the future.
However, Shakespeare claimed that there is currently no deal in place to take the Leicester academy graduate to Old Trafford on a permanent basis.
"We have not heard anything to that effect [that the club have agreed a deal],” Shakespeare told reporters.
"It is an on-going situation, as reported before. There is no change in that."
|MAN UTD LATEST
|14/1||United are 14/1 with Bet365 to beat Norwich City 4-0 on Saturday afternoon
While not a first-team regular at King Power Stadium, Schlupp has made a total of nine appearances for the Foxes so far this season, and Shakespeare insists the player is still part of the club.
"Jeff was at the game on Tuesday [during Leicester City's 3-0 win over Blackburn Rovers] and came in to see the lads," he said.
"We are in constant dialogue with Jeff and Manchester United. Again it is a situation we are at ease with."
The 20-year-old German-born striker is scheduled to appear in a further Under-21 fixture for United, however, Leicester are also able to recall the player at any time if needed.
Shakespeare continued: "He is due to play another game for them and then we will take it from there.
"It is open-ended but they are not going to keep him for six months and not make a decision. But at the same time, if we feel we need to use him here we will. It is all very relaxed."