Rangers were dealt a major blow today when influential defender Carlos Cuellar was ruled out of the crucial Champions League qualifier in Lithuania with FBK Kaunas.

The Ibrox outfit were hoping to have the Spaniard available for tomorrow’s second leg after he missed the disappointing scoreless draw at Ibrox last week with a calf injury.

The Gers could have done with all their top players given the importance of this week’s game with potentially around £20 million riding on the result.

As Rangers prepared for their flight this morning, assistant boss Ally McCoist admitted Cuellar would miss out.

He said: "I wouldn't have thought he would play.

"There has been a vast improvement with his calf but it looks as though the game has come too quickly for him."

Rangers, who lost 4-0 in a friendly at home to Liverpool on Saturday, are likely to play Danish side Aalborg in the final qualifying round if they progress.

But there is also a real threat of crashing out of Europe completely unless they show a vast improvement tomorrow night.

McCoist added: "It's a big test for us early in the season and it's a game that we need to get a result in if we want to play European football - it's as simple as that.”

While Rangers face a crunch European match, Celtic, who won 3-1 against Feyenoord last night, are feeling the pressure of getting new players in ahead of the SPL campaign which starts this weekend.

So far only winger Pat McCourt from Derry City and Georgios Samaras on a permanent deal from Manchester City have arrived with Barcelona midfielder Marc Crosas hoping to follow them.

Celtic boss Gordon Strachan said: “We are trying our best to sign players at the moment. I hope the squad can be added to before the start of the season. If it doesn't I’ll get on with it.”