The Bristol City player, 24, who spent a loan spell with Rotherham last season - making nine appearances - was a transfer option for Warne, but priorites elsewhere have dictated that the Millers did not actively pursue a move with the way left the way clear for Hull.
Warne said: "I loved Haks and in fairness I spoke to the Hull manager, he phoned me for a recommendation for him and I said, 'I am sort of still interested but not a 100 per cent because I am trying to get something else through'.
"No offence to Haks but I do need something else before I need a winger.
"I couldn't lie to the manager so I told him if you can get him, get him and he begged me not to go for him.
"I think he will do brilliantly at Hull, I really like Grant and I wish him (Adelakun) all the best and maybe our paths will meet at a different time.
Parent club Bristol City have a recall clause on Adelakun which they can exercise in January.