Rossiter will join Rangers in the summer transfer window after leaving Premier League outfit Liverpool.
According to The Daily Mail, Rangers will have to pay a sum in the region of £250,000 for the services of the 19-year-old midfielder.
Warburton believes that Rossiter will be worth a lot of money in the coming years.
“I think he will be worth a lot of money — quicker than three or four years from now,” the Rangers boss told The Scottish Sun about Rossiter.
“The fact of the matter is the southern market has much deeper pockets so an ideal scenario is they come here, we do what we have to do, we get Champions League football and then in two or three years’ time we lose a couple of assets to Premier League clubs then everyone is happy.”
Rossiter is a very talented young player, and there is a very good chance that he will get better and improve further in the coming years.
Rangers have just returned to the Scottish Premiership, and the youngster will hope to play an important role for the Gers in the top flight next season.
It is hard for clubs in Scotland, even for Celtic and Rangers, to keep hold of their best players when teams from England come calling.