Bangalore: Beaten by Warriors in the opening match, Royal Challengers Bangalore suffered a big setback ahead of their crucial Champions League encounter against Kolkata Knight riders on Thursday with star wicketkeeper batsman AB de Villers ruled out of the T20 tournament because of a finger injury.

The South African broke his left middle finger during their practice on the eve of their second group B match against KKR and will be flying back home to undergo a surgery.

In the absence of de Villiers, either Sri Lankan import Tillakaratne Dilshan or KB Arun Karthik is likely to don the gloves.

Both teams will be desperate for a victory as another defeat would severely dent their chances of a semifinal berth as only top-two teams in each Group would make the last-four stage.

The talent in RCB ranks can hardly be questioned but the results are yet to be seen. Their batsmen were diligent against Warriors, posting a challenging total but it was their bowlers, who failed to stem the run flow and snatch defeat from the jaws of victory.

All eyes will be on the marauding Chris Gayle, who can single-handedly take the game away on his day, as he did against KKR at the Eden during the last edition of Indian Premier League.

The hard-hitting Jamaican was not in his imperious and dominating self against Warriors. Gayle was off to a rollicking start, smashing 23 off 14 balls, adorned with two hits to the fence and two over it but could not sustain the tempo.

However, the injury-induced absence of de Villiers has come as a jolt for the home team.

Top batsman Virat Kohli said de Villiers' absence will affect the balance of the side, with more responsibility on his shoulders.

"Unfortunately AB has broken his finger during practice and he is flying back home. We are not yet sure, who is going to keep the wickets. The replacements keeper might be Arun Karthik or Tillakaratne Dilshan but it will be decided by tomorrow," the RCB skipper said.

Saurabh Tiwary and Mohammed Kaif also chipped in with useful scores in the first match. Leading the pace attack will be left-arm bowler Dirk Nannes and Karnataka seamer Sreenath Aravind.

RCB has another talented fast bowler in Abhimanyu Mithun, but the India-discard has not lived up to his billing.

The spin department will be shouldered by skipper Daniel Vettori. Led by Gautam Gambhir, KKR lacked the wherewithal against the rampaging Redbacks on Tuesday night.

Baring Manoj Tiwary's 36-ball 40, their batsmen failed to post a worthy score while the bowling looked out of sorts with Brett Lee and Iqbal Abdulla giving away runs at ease.

Gambhir, the most expensive player, sold for a whopping $2.4 million, too would be eager to get back into the grind as the left hander is coming into the tournament after suffering a concussion and didn't make a great start into tournament, scoring a mere nine runs against Redbacks after failing to open his account against Somerset.

The KKR smarting under three defeats in a row, need to rework on their bowling department, as the frontline bowlers are turning out to be expensive.

Against the Redbacks total of 188, KKR could only manage 169/9 to fall 19 runs short of the winning target.