Warburton has been a huge success since taking charge of Glasgow Rangers last season.
Gray previously worked with Warburton at Brentford, helping to guide the London club from League One into the top half of the Championship.
Warburton has continued to impress since leaving, guiding Rangers to the Scottish Premiership and the Scottish Cup final in his first year in charge at Ibrox.
He is now looking to turn them into serious contenders to Celtic’s dominance and Gray has backed him and his assistant manager David Weir to go all the way with the Gers.
“I don’t see why he cant make it to a big English club,” he told the Daily Mail.
“He’s still learning and he’s only going to get better. Knowing him and Davie [Weir] as I do, I’m sure they’ll go all the way with Rangers. Celtic are always going to be up at the top but I think Rangers are going to be up there too.”
It now remains to be seen if Warburton can lead Rangers to the Scottish Premiership title this season.
Things did not get off to the best of starts on Saturday as Hamilton Academical held them to a 1-1 draw at Ibrox.
That game showed that this season is likely to be a tough one for the Gers, and should Warburton lead them to success then there is no denying that his star will continue to rise.