SEAN LONGSTAFF is set to follow Ayoze Perez through the St James’ Park exit door, with Manchester United poised to table a formal £25m offer for the Newcastle midfielder.

Perez’s £30m switch to Leicester City was confirmed yesterday morning, at the same time as Longstaff was returning to Newcastle’s Darsley Park training ground with the rest of the Magpies’ non-international players.

With Newcastle still to appoint a replacement for Rafael Benitez, Under-23s coaches Neil Redfearn and Ben Dawson took joint charge of training, but the pair might not be working with Longstaff for long if Manchester United get their way.

Ole Gunnar Solksjaer is determined to reduce the average age of his Old Trafford squad this summer, and having already recruited Daniel James and Aaron Wan-Bissaka, the Manchester United boss has instructed his club’s recruitment team to do what they can to sign Longstaff.

The 21-year-old was one of the breakthrough stars of last season, even though a knee ligament injury restricted him to just three months of first-team action.

That was sufficient to see him linked with a possible call-up to Gareth Southgate’s England squad, and has resulted in Solsjkaer awarding him a prominent position on his wanted list.

Unlike Perez, whose contract contained a £30m buyout clause, the Newcastle hierarchy will not be compelled to sell Longstaff if Manchester United table a £25m bid.

However, Mike Ashley could find it hard to turn down such a lucrative sum for a player with just eight Premier League starts to his name.

That said, however, selling Lonsgtaff so soon after Perez’s departure would hardly send out the best of signals, with Lee Charnley hoping to appoint Benitez’s successor before Newcastle’s first-team squad head out to China for the Premier League Asia Trophy later this month.

Perez will not be part of the squad that travels to the Far East after he signed a four-year contract at the King Power Stadium to complete his switch to Leicester.

Spanish clubs Valencia and Real Betis had inquired about securing Perez’s services earlier in the summer, but the 25-year-old was happy to turn his back on a possible return to Spain in order to join a Leicester side that finished in seventh position in the table under new boss Brendan Rodgers.

“I’m very happy and very pleased,” said Perez. “I’m very proud to be part of the Leicester family and I can’t wait to get started.

“The club want to keep growing as much as they can and that’s something I like. I spoke with the manager and that was important. That made me feel very comfortable about the decision to come here.”

Perez joins a Leicester forward line that already features Jamie Vardy, Shinji Okazaki, and Kelechi Iheanacho, but Rodgers is delighted to have prised the Spanish striker from Tyneside, having been impressed by his performances as he scored 13 goals in all competitions last season.

“I think Ayoze will be a wonderful addition to the squad,” said the Foxes boss. “He’s quick, has a good eye for goal and he’s experienced in the Premier League too.

“I think he’s a player who will excite our supporters, and his style is one that I believe complements the options and quality that we already have here at the football club.”

Meanwhile, Newcastle face a huge battle to persuade Roberto Martinez to give up the chance of leading Belgium to Euro 2020 glory in order to take over at St James’ Park.

Martinez is one of Newcastle’s leading candidates to replace Benitez, and the Magpies hierarchy are understood to have opened up an informal line of contact to the 45-year-old and his representatives. Newcastle are yet to make a formal approach to the Belgian FA, but a move is anticipated.

However, while Martinez is keen to return to the Premier League, having last managed in the English top-flight in 2016, he is also desperate to lead Belgium into next summer’s Euro 2020 finals, where they will almost certainly start as one of the favourites to lift the trophy.