The Gers suffered their first defeat of the season this evening, as they went down 3-1 to St Johnstone in the third round of the Scottish League Cup at Ibrox.
Following the match, Warburton admitted that his Rangers team failed to match their opponents from the Scottish Premiership.
"Credit to the opposition,” the Englishman told BBC Scotland. “They came with a game plan and they got their rewards in the first half. We've been together since June 27th. It's 11 new players.”
Murray Davidson gave St Johnstone the lead in the 19th minute, Simon Lappin doubled the advantage just before the half-hour mark, and Michael O’Halloran made it 3-0 in the opening minute of the second period.
James Tavernier pulled one back for Rangers just past the hour mark, but it proved to be nothing but a mere consolation in the end.
Over the course of the 90 minutes at Ibrox, hosts Rangers had 62% of the possession, took 12 shots of which only two were on target, and earned four corners.
Visitors St Johnstone had 38% of the possession, took six shots of which four were on target, and earned two corners.