Ex-Hearts ace Jason Holt trains with Rangers
Warburton is keen to sign a creative, attacking midfielder but has so far been rebuffed in his attempts to lure Scott Allan away from Hibs. Holt also fits the bill and is available for a modest compensation fee due to Hearts.
He is being assessed by Warburton and his assistant David Weir, who want to reinforce their squad and gain promotion from the Scottish Championship this season.
Holt, 22, scored five goals in 17 appearances on loan at Sheffield United during the second half of last season. He left Hearts hoping for more regular game time and now has the opportunity to prove himself to the Rangers management team.
His contract at Tynecastle has expired and he is a free agent, however Hearts are due a development fee for bringing the player through their youth academy. They are not expected to be difficult to deal with, however.