Manchester United and Sporting CP are in the final stretch of reaching an agreement over Bruno Fernandes' fee.
The Sunsays Fernandes' proposed move to United from Sporting has been delayed because the Portuguese club are not satisfied with the payment scheme United are offering.
The 25-year-old has been linked with a move to the Premier League ever since his sensational 2018-2019 season, in which he scored 33 goals in 53 games for Sporting.
It looked like he was nearing a move to Old Trafford, and it was expected that Sporting's Friday night game against Benfica would be his final appearance for the club.
But United's offer of £34m plus a further £25.5m in add-ons is not acceptable for Sporting as they do not believe they will ever see the money which is linked to achievements, including bonuses if United win the Premier League or Champions League.