Hayes and Yeading United defender Ronnie Bull who was dual registered with Exeter City has signed a contract for the League Two side and is no longer part of the Church Road set up.
The former Millwall defender came to United effectively on loan from Exeter earlier this season and played a number of games in the left back spot.
At the same time was was getting back to full fitness by also training and playing for Exeter City Reserves.
According to Exeter boss Paul Tisdale, Bull has now forced his way into first team contention with the Grecians who are currently pushing for a play-off spot in League Two.
He has been rewarded with a contract until the end of the season.