Louis van Gaal arrived at Manchester United’s training ground on Monday morning as his reign at Manchester United drew to a close.

The Dutchman arrived at around 8.45am, his Mercedes sweeping into the Carrington training ground. The renowned lawyer Paul Gilroy QC, who works for the League Managers Association, also arrived soon after, initially being denied entry to the training ground.

The club has announced that an announcement will be made at 1pm BST, when the New York Stock Exchange opens for business. United also have some shares on the Frankfurt exchange, which briefly opened up 2.4% higher before falling to 2.6% lower than their opening price.

Ryan Giggs, United’s most decorated player and assistant to Van Gaal, was seen leaving the training ground shortly after Van Gaal’s arrival, fuelling speculation that he could also leave the club.

Two years ago the Dutchman’s predecessor, David Moyes, attended an early-morning meeting with the executive vice-chairman Ed Woodward at the training complex and a statement confirming the Scot’s sacking followed shortly afterwards, just 10 months into a six-year deal to replace Sir Alex Ferguson.

After a disappointing campaign in terms of style and substance at Old Trafford, albeit one which realised an FA Cup win, another change is imminent as José Mourinho prepares for a return to management.

United have steadfastly refused to comment while the Portuguese kept his counsel when asked about the job before David Haye’s fight at London’s O₂ Arena on Saturday evening.

Van Gaal stood firm when asked about his position in the post-match press conference at Wembley, but told a reporter on Sunday outside the team’s London hotel that “it’s over”.

Gilroy, who has represented the former United manager Sir Alex Ferguson and England’s Roy Hodgson in the past, has been described as a “tenacious and personable” lawyer who “is renowned for getting a fantastic deal for managers”.

Van Gaal still has a season remaining on his three-year contract, while Mourinho has been out of work since paying for Chelsea’s abysmal title defence with his job in December.

The Portuguese has repeatedly spoken of his plan to return to work this summer, and reviving United’s fortunes would be a mouth-watering proposition.

United, a club synonymous with a swashbuckling, attacking style, managed a paltry 49 league goals – their lowest return for 26 years – and missed out on Champions League qualification to neighbours Manchester City on goal difference.

A first FA Cup win since 2004 was a welcome boost, but Wayne Rooney knows the campaign was far from good enough. “He has been under pressure. I think we all have,” the captain said of Van Gaal.

“That’s part of playing for Manchester United and managing Manchester United – it is a massive club. You have to set standards and we fell below them this season. But we have to make sure as players we get back to those standards and make sure we are back challenging for the main trophies.”

Success is something the former United midfielder and Chelsea assistant coach Ray Wilkins is backing Mourinho to bring back to Old Trafford.

“I think it is the right move,” he told Talksport. “It is the only move for them. He will get them playing again and he will get them winning again. He is a winner – there is no two ways about it. When he goes to a club, normally he wins a big trophy within the first couple of years.”