Chelsea's Russia international defender Yury Zhirkov has pledged to show the fans he is worth his £18million price tag.
Zhirkov is set to play against Spartak Moscow in the Champions League at the Luzhniki Stadium tonight as Group F's two unbeaten teams face each other.
Zhirkov left CSKA Moscow for London last year but suffered a knee injury that has restricted him to just 27 appearances for the Blues.
But the 27-year-old left-back insists he is now ready to show his real value after admitting he has failed to produce his best form so far.
"I've not lived up to my full potential because I haven't played too many games in the first team," admitted Zhirkov.
"But I'll try to show more. I'm getting fitter game by game, and I'll try to show more. My fitness is getting better and I'm feeling more confident."
Zhirkov was linked with a move back to Russia with Spartak in the summer but the defender was quick to dismiss the talk.
"It is just rumours and speculation," he said. "I don't want to leave Chelsea and if the manager doesn't want to sell me, I will stay."
Boss Carlo Ancelotti, wrestling with an injury crisis ahead of tonight's game, insisted Zhirkov was a vital part of his squad.
"He had a very good season last year," said Ancelotti. "He was fit to play our more important games towards the end of the season, when he didn't have an injury he played important games.
"He played when Ashley Cole had an injury, and played very important games. For me Yury is a very important player, he didn't start a lot of games but you can't say he is not important.
"He can play a lot of positions on the pitch, he played very well as a left-back and as a midfielder. He is a very important player for us and I never thought he could leave Chelsea."
Meanwhile, Ancelotti is adamant captain John Terry will not suffer from any psychological problems when he plays at the Luzhniki for the first time since Chelsea lost to Manchester United in the 2008 Champions League final.
Terry slipped as he took the penalty that would have given Chelsea their first European crown but Ancelotti does not believe he will be affected.
"John has great experience so I think what happened two years ago has no effect on him, he has experience," said Ancelotti.
"Everyone knows in football you can sometimes lose games. I lost a final in 2005 but you have to look forward. If you look forward with enthusiasm and character you can have revenge.
"Chelsea lost the final in 2008 but I don't think they will have a psychological problem with that tomorrow, it is a different story now."
Chelsea confirmed Brazilian midfielder Ramires is the latest addition to their mounting injury list. He collected a knock against Aston Villa on Saturday and will return home today to begin treatment.
Chelsea are already without strikers Didier Drogba and Daniel Sturridge, defenders Alex and Jose Bosingwa and midfielders Frank Lampard and Yossi Benayoun.