Manchester United manager Ruben Amorim needs three years to prove he is a "great" coach, says co-owner Sir Jim Ratcliffe. Amorim will complete a year at the Old Trafford helm in November but his record since arriving from Portuguese club Sporting has not been good. United finished 15th in the Premier League last season, their worst performance since the 1973-74 campaign in which they were relegated from the top flight. Despite a summer transfer outlay in excess of £200m, they have already lost three times in the league this season and been knocked out of the EFL Cup by League Two Grimsby. Although sources close to Ratcliffe had stressed Amorim was not in any immediate danger, a fresh round of speculation before last weekend's 2-0 victory over Sunderland suggested Amorim was at risk of losing his job if United had failed to win. However, in an interview on the Times' The Business podcast, Ratcliffe says that was not the case and feels "good guy" Amorim will need an extended amount of time to prove his worth. "He has not had the best of seasons," said Ratcliffe. "Ruben needs to demonstrate he is a great coach over three years. That's where I would be."