Ryan Nelsen believes West Ham have issued a statement of intent by tying Winston Reid to a new deal.
Tottenham are keen for striker Shaquile Coulthirst to continue his development out on loan after his spell at Southend.
Just 18 years old, McGahey has shone for the first team in recent weeks having been promoted through the ranks due to his impact on the Seasiders' under-18s team.
McGahey is one of three younger players to have been offered new terms and Ferguson believes Blackpool, whose Sky Bet Championship status is not yet secured with a game remaining, should do everything in their power to keep him.
He said: "Blackpool have one hell of a player on their hands and they need to get him sorted out, otherwise they'll miss out on a top player.
"It's important because he's an excellent player. He's such a grounded boy and I like that. He's last off the training pitch and he still helps the staff bring the kit in.
"That makes me smile because you don't see that too often. He cleans my boots too! I like him a lot."