Ibrox side Glasgow Rangers are trying to add more players before the season starts.
Rangers are seeking additions to their current squad, as Warburton looks to put the finishing touches on his team before the new campaign starts up.
Rangers are still reportedly looking to add a centre-back and a striker, even though they have completed nine transfers this summer.
Warburton admits that his options are decreasing by the day, though, and he insists that Rangers simply cannot get into bidding wars with clubs south of the border.
“We are trying, it's an ever-decreasing talent pool,”said Warburton. “You look at the prices down south and there are players moving for six, seven, eight or £10million who were one, two, three, four million just a few weeks ago.
“The market demand is such that the shelves are getting thin after the Euros. People are now starting to panic and Rangers can't be drawn into that. We can't be drawn into a panic buy.
“If it adds value, we will make a move, but we won't be drawn into an auction because we will lose that.”
Rangers have already been one of the most active sides in Scotland over the summer transfer window.
The Light Blues have brought in a whole host of players to help add depth to their squad, as they look to compete back in Scotland’s top flight.
Rangers have made a promising start to the new campaign, by winning their first two competitive matches.
Rangers’ competitive season gets underway with a match against Hamilton at Ibrox at the start of next month.