Kyle Bartley has backed Rangers to recover quickly from the defeat at Celtic Park and return to winning ways on Monday.
"If we win against Motherwell and Celtic lose their game then we go back on top again so we are staying positive," said the defender.
"Of course it's hugely disappointing to lose three points at this stage of the season but we have to take it on the chin and move on.
"Everyone gave 100% but we have lost the match and we can't come up with any excuses."
Rangers felt they should have taken the lead early in the game when a Lee Wallace header appeared to cross the line but the 'goal' was missed by the match officials.
However, Bartley - who replaced the suspended Dorin Goian at the heart of defence - was just as disappointed with the Joe Ledley goal Rangers conceded from a corner.
He added: "We talked at half-time about how set pieces could be crucial.
"You can't switch off for a moment in games like these but unfortunately we did and it cost us.
"I thought Celtic defended really well and we found it hard to create chances in the second half."
The on-loan Arsenal defender added: "For me it was a great experience to play in the game and that's why I came to Rangers.
"It was fantastic to play beside someone like Carlos Bocanegra who has so much experience and I can only learn from him."
Meanwhile, Rangers legend Derek Johnstone insists Ally McCoist must be given funds to strengthen his squad in January - whether star striker Nikica Jelavic moves on or not.
"I think it's so important that Ally brings in some faces," he said.
McCoist last night played down speculation of a written offer for Jelavic from QPR as "just a rumour" and was unable to confirm their interest.
But Rangers could face a battle to retain the services of the striker, who has netted 14 goals this season.
The Croatian was the subject of a failed £6.5million bid from Leicester in August and the champions could find their resolve tested again.
Johnstone added: "If they are going to get big money for him, I can understand why Craig Whyte will take the money. But you can't just take him out of the side and not bring anybody else in.
"Ally has got to have some money, even if it's a loan deal, to bring in another striker.
"Even if Jelavic does stay, I think he still needs a striker anyway, somebody fresh to come in.
"He probably needs a creator in midfield as well because there is no spark there."