Centre-back Maguire moves to the KC Stadium after Sheffield United ‘reluctantly’ accepted a £2.5m bid for their defensive stalwart on Monday.
A deal for the defender looked dead last week with the clubs unable to find an agreement on a fee but the 6ft 4in centre-back has now signed for Steve Bruce’s side after an accord was reached.
Maguire, who made 166 appearances for United since joining the club’s youth side from Barnsley five years ago, admitted his relief that the deal has finally gone through
“Ever since I knew Hull were interested it was a deal that I wanted to complete and go through,” the 21-year-old told Sky Sports News. “It took a long time but in the end I am here.
“It’s been a whirlwind, the clubs were trying to agree a fee and I’ve just been sat waiting. Obviously since I knew Hull were wanting to get my signature, I couldn’t really turn it down, the opportunity to play in probably the best league in the world and obviously the chance to play in the Europa League.
“It’s going to be a massive challenge for me and one that I am looking forward to. I think if I’m not ready (to step up) now I’ll never be ready so I think I need to do everything I can to take the opportunity I’ve been given.
“Playing week-in, week-out, is different to playing against some of the best players in the world, but obviously it’s something I think I can cope with otherwise I wouldn’t be here.”
Scotland international left-back Robertson has also joined the club after moving south of the border from Dundee United for a fee of £2.85m.
It caps a meteoric rise for the 21-year-old who was plying his trade for Scottish amateur side Queen’s Park just 12 months ago.
“I’m delighted it’s (the deal) over the finish line now and I’m just looking forward to meeting the boys and getting started,” he said.
“Obviously I’ve come from United up the road and that was brilliant for me but I think this is just the right step for me and I’m looking forward now to playing in the biggest league in the world. I’m relishing it.
“I’ve got belief in myself and my ability that hopefully I can push for a place in the starting XI.”
Dundee United have signed Conor Townsend from Hull on loan until the end of the season as a replacement for Robertson.