He said it was difficult to convince players to move to Old Trafford after he took charge at the end of last season.
“I see a big difference in comparison with last year,” Ten Hag said.
“Now many players see the project, what’s going on, the dynamic and the ambition.”
Last summer midfielder Casemiro joined from Real Madrid for £70m and United also signed midfielder Christian Eriksen, forward Antony and defenders Lisandro Martinez and Tyrell Malacia during the summer transfer window.
Netherlands forward Cody Gakpo was heavily linked with a move from PSV Eindhoven in December before moving to Liverpool.
Ten Hag said: “There were a lot of reservations last year, a lot of doubts when we approached players. This year many quality players really want to come.”
Qatari banker Sheikh Jassim bin Hamad Al Thani and Sir Jim Ratcliffe’s Ineos Group, who have submitted bids for United, are the two main parties looking to take control.
United’s owners, the Glazer family, have yet to name a preferred bidder.
United, who won the Carabao Cup in February, face Manchester City in the FA Cup final on 3 June.
The club has been linked with a number of players including Tottenham Hotspur striker Harry Kane.
Ten Hag said expectations would be higher next season but they were making steady progress.
“We have to rebuild and reconstruct,” Ten Hag said. “We are in that process and in the right direction. You can see that in the way we play.”
Goalkeeper David de Gea is in talks over a new contract, although there have been reports that he may not be first choice next season.
The 32-year-old has been criticised this season, most recently after his error proved decisive in the 1-0 league defeat by West Ham last weekend.
Ten Hag said uncertainty over De Gea’s future was not behind his loss of form.
“Every top football player, there’s a high demand,” Ten Hag said. “You have to accept it, deal with it, and the demand is you have to perform.
“I don’t think that’s a reason because David is so experienced. I can think about a thousand and one reasons but I don’t think that’s the reason.”