Manchester United signed a £750m 10-year shirt deal with Adidas in August, after Nike ended its relationship with the team
The football club predicts that profits and revenues will fall in 2015 after failing to qualify for the Champions League for the first time in 20 years.
The prediction comes as it reports a plunge in profits, despite record revenues for 2014.
Net income fell 84% for the year to 30 June to £23.8m, down from £146m a year ago.
Manchester United said that was due in part to last year’s profit being boosted by a one-off tax credit, without which it would have made a loss.
The club, majority-owned by the American Glazer family, said revenue increased 19% to £433.2m in the 2013-14 financial year, thanks to improved TV and sponsorship deals.
However, that is now predicted to fall to between £385m and £395m.
Similarly, underlying profits were £130.1m for the year to 30 June and that is now forecast to fall to between £90m and £95m.
The results also showed that David Moyes and his backroom staff received a total of £5.2m in compensation following the former Manchester United manager’s sacking in April after less than a year in the job.
Ed Woodward, executive vice chairman of Manchester United, said: “With Louis van Gaal at the helm as manager, and the recent signing of some of the world’s leading players to further strengthen our squad, we are very excited about the future and believe it’s the start of a new chapter in the club’s history.
“Louis’ footballing philosophy fits very well with Manchester United and he has an impressive track record of success throughout his career, winning league titles with every club he has managed.”
However, with only two points from their opening three Premier League games, in addition to a shock Capital One Cup defeat by MK Dons , Van Gaal’s reign has not started well.
In July, Manchester United announced a record breaking £750m 10-year shirt manufacturer sponsorship deal with Adidas, after Nike decided to end its association with the club at the end of the 2014-15 season.
Nike had been given a period of exclusivity to negotiate an extension with United and also retained the right to match any other offer.
But the company decided against exercising either option, claiming the terms “did not represent good value for Nike’s shareholders”.
Champions League winner Real Madrid’s £31m-a-year deal with Adidas was previously the biggest club deal.
Adidas will provide training and playing kit to all the club’s teams and will have the exclusive right to distribute dual-branded merchandising products worldwide.