Bradford City have rejected Sheffield United's approach to speak to boss Phil Parkinson, BBC Radio Sheffield reports.
It is understood there is figure that would trigger a release clause in Parkinson's contract but the Blades have failed to meet it.
Parkinson, 47, is under contract at Bradford until the end of next season.
In the 2012-13 season, his first full campaign as manager, Bradford became the first League Two side to reach a major Wembley final when they appeared against Swansea in the League Cup.
The Bantams were then promoted at Wembley at the end of that season by winning the play-offs.
This season, Parkinson took the team on a memorable run to the quarter-finals of the FA Cup, coming from 2-0 down to beat Premier League champions Chelsea 4-2 at Stamford Bridge, before beating Sunderland 2-0 in round five.
Sheffield United are set for a fifth successive season in League One.