Sofyan Amrabat is undergoing a medical as part of a deadline day switch to Manchester United.
The Moroccan international emerged as the Red Devil's No 1 midfield target and the club now look close to getting their man.
The Red Devils will pay an £8million loan fee and their deal will include the option to buy Amrabat for £21m at the end of the season.
Mail Sport understands Fiorentina would have preferred an obligation rather than option to buy.
However, it is understood a sizeable loan fee of £8m was considered a reasonable compromise
This comes after Manchester United's director of football negotiations Matt Hargreaves flew to Italy in order to seal the deal for Amrabat.
Mail Sport understands that the option to buy Amrabat must be triggered by May, and if it isn't taken up by United, there's room to manouvre for Fiorentina before Amrabat's contract runs out.
When asked about how he feels about the strength of his Man United squad after the deal for Amrabat, Ten Hag told the press: 'I think we have done good business.
'We constructed a strong squad and we are ready for the fight.'
Ten Hag has finally got his man despite tough negotiations with the Serie A side all summer.
Fiorentina president Rocco Commisso revealed that they would allow the Moroccan to leave providing the deal suited the club.
'We told Amrabat that if he has an opportunity to leave, then we'll let him go,' he said.
'If this deal cannot be done, then he has two years left on his contract and will remain.
'There are many negotiations in progress. I don't want to name names. So wait 24 hours and then you'll know what happens.'
Amrabat is yet to play this season for Fiorentina as he has