‘He’s one of the most outstanding players’ - Portsmouth boss' praise after arrival of Sunderland, Derby and Brentford target

And while the head coach believes the 19-year-old has an exciting future, he insists the midfielder is ready to play a key role with Pompey next season.

The Blues fended off interest from Sunderland, Derby, Brentford and Stoke to land the Northern Ireland youth international on the second day of the transfer window.

It represented months of hard work to secure his signature, with sporting director Rich Hughes and head of recruitment Phil Boardman paying four visits to Glentoran last term.

Indeed, their trips across the Irish sea paid off, with Pompey signing Devlin for a fee believed to be £90,000 and penned a three-year deal with a club option of a further 12 months.

Although first-team fixture commitments prevented Mousinho from watching the midfielder in person, a wealth of clips and character references rubber stamped the move for the Blues boss.

He told The News: ‘Terry is a player the recruitment department has tracked for a while now.

‘He was one of the most outstanding players in the league in Northern Ireland last season and a real young up-and-coming potential. In terms of what the limit is, who knows what he can achieve in his career, hopefully we can help facilitate that.

‘Plenty of clubs were tracking Terry and there was a huge amount of interest, so we were really, really pleased we managed to get him.

‘Not only does he have a huge amount of potential in the future, but he’s one who can impact the team this year based on what we’ve seen from his time at Glentoran.’

Devlin spent just one season at the Bet McLean Oval, but shone in the Northern Irish Premiership, where he appeared 32 times and scored on two occasions.

Pompey now have five first-team midfielders contracted for next term and Mousinho explained what the youngster can bring to the Blues’ engine room.

He added: ‘I would describe him as an all-rounder. Probably a bit more attacking than defensive, slightly more advanced.

‘He’s a powerful runner, a very athletic kid, gets into the box, he’s aggressive and has a decent enough eye for goal.

‘He’s all action and can be one of those who is a box-to-box midfielder. Primarily in the system we play we’ll see him a bit more advanced.’