The former Glengormley Integrated Primary School student signed for the east London outfit on January 4, having made five appearances (three as sub) and scored once for the Linfield first team (in the side’s League Cup win against PSNI in November).
Since putting pen to paper for the London Stadium outfit, well wishes have been extended to the promising player.
Speaking to the Times, Callum’s dad Ciaran said: “Words can’t describe how proud both his mum and I are of him, but he’s put in the hard work and dedication to get to where he is and deserves everything he’s achieved.
“This is only the start of an even bigger challenge.”
Callum’s former primary school also took to social media to wish him well.
Commenting on Facebook, a spokesperson for Glengormley Integrated Primary School said: “An enormous well done from all at GIPS to past pupil Callum Marshall who is now officially a West Ham player!
“Callum always displayed talent and a great attitude on the pitch (and in class).
“Callum was incredible when representing the school football team- scoring goal and after goal and supporting everyone around him! We wish you every success for the future!”
Linfield manager David Healy also took the opportunity to wish his former player well.
Speaking to the Linfield FC website, Healy said: “I want to wish Callum every success with this exciting new challenge that he’s now setting out upon. It’s a wonderful opportunity for him at such a leading Premiership club in West Ham United.
“He’s been training with our first team squad all season and he’s made a very positive impression on all our players and staff.
“We are sure he has the attitude and determination that will be required to make the most of this amazing opportunity that has come his way.
“Everyone at Linfield is delighted with the recognition that both Callum and the club’s Scholarship scheme has earned and we will all be monitoring Callum’s progress with a keen interest.”