Cuellar will return to the Rangers back four for Thursday's semi-final second leg against Fiorentina in Italy after missing Sunday's Old Firm derby through suspension.

Fiorentina are favourites to progress after a blank first leg but Rangers have already knocked out Panathinaikos and Sporting Lisbon after goalless games at Ibrox.

Cuellar was badly missed at Celtic Park as the home side won 3-2, with the Rangers back four looking further exposed after fellow-centre back David Weir limped off with with a groin injury early in the second half.

Weir is now a doubt for the game in Italy, while midfielder Steven Davis is also causing concern with a groin problem.

But Cuellar is desperate to repay Walter Smith for the faith he has shown in him since last summer and he believes they can keep the club`s quadruple bid going in Florence.

"My feelings are very positive," the Spaniard said. "We were very focused throughout the whole match and Fiorentina did not have too many chances to score.

"I think that we have a great opportunity to reach the final. We can win and get through in Italy."

Cuellar, who was named the Clydesdale Bank Premier League Player of the Year earlier this month after his solid performances since a £2.4million move from Osasuna last summer, recently claimed he would love to stay at Rangers for life and today revealed Smith had been a huge factor in his seamless transition to the Scottish game.

"It makes me very proud," the 26-year-old told Spanish newspaper Marca.

"It is very difficult to obtain this award and it is recognition for the good season I have had.

"I have to also thank my team, who have helped me be named the best player in the Scottish league thanks to their good work.

"I arrived with high hopes and thanks to all the confidence they have given me I have adapted very well to this football.

"It is different to Spain and I am already totally integrated in Scotland.

"We are alive in all the competitions that we are disputing. I am playing a lot of minutes, I have played in the Champions League, we have a chance to win the UEFA Cup.

"The coach has given me a lot of confidence since that first day that I arrived in Glasgow and I am trying to respond in the best way possible.

"We are doing something very difficult and I hope to have won everything at the end of the season."

While Cuellar is clearly relishing life at Rangers, he admits playing in Scotland is not doing his international chances much good.

Cuellar has never been capped by Spain and is unlikely to break into Luis Aragones` squad before the European Championship finals.

"I don`t think that anything is closed, but it is much more difficult to get in," he said.