Their fate hanging in balance, a loss in the penultimate league round match may virtually sound the death knell for one of the two teams.
It's a mad scramble for the two available play-off berths with five teams including KKR and RR, who are tied on 12 points, remaining in the hunt.
To make the competition stiffer, both the teams have picked up late momentum in the business end of the tournament.
Down after back-to-back defeats, KKR bounced back with a bang, posting the fourth highest total of the IPL -- 245/6 -- to down Kings XI Punjab by 31 runs in their last match.
From being on the verge of elimination, RR too have returned to the reckoning with a hat-trick of wins, thanks to the imperious form shown by Jos Buttler who was adjudged man-of-the-match in all the three victories.
The RR opener struck an unbeaten 94 to seal an easy seven-wicket win over Mumbai Indians last night. This was the English wicketkeeper-batsman's fifth consecutive half-century -- an IPL record jointly held with Virender Sehwag.
His scores in the last five innings read 67, 51, 82, 95*, 94* and Buttler along with allrounder Ben Stokes, who has played in different positions in the batting order, will be the two major threats for KKR.
Half of their battle will be won if the Dinesh Karthik-led side can dismiss the English duo cheaply. The skipper will look to go all out with their spin attack to exploit their weakness.
With the Eden Gardens slated to host Eliminator and Playoff Two, KKR may have a chance to play again at home if they can finish at third or fouth position in the IPL table.
Rahane has 280 runs from 12 innings with a woeful average of 28.00 and it's high time that he returns among runs to give their batting a stability.
Narine slammed 75 off 36 balls, while Karthik smashed a 23-ball 50 in their big total in Indore.
With his exploits with both bat and ball, Narine has emerged as the most valuable player for KKR and the Trinidadian will once again look to play a key role.
Narine's battle with Buttler will be one of the key contests of the game.
Skipper Karthik has quietly done his job in the batting and averages a healthy 46.37 (371 runs) and he too will eye a good show with the bat tomorrow.
Nothing much separates the teams in terms of head to head (7-7) count and it seems another mouth-watering contest might be on the cards.
Kolkata Knight Riders: Dinesh Karthik (c), Sunil Narine, Andre Russell, Chris Lynn, Robin Uthappa, Kuldeep Yadav, Piyush Chawla, Nitish Rana, Prasidh Krishna, Shivam Mavi, Mitchell Johnson, Shubman Gill, R. Vinay Kumar, Rinku Singh, Cameron Delport, Javon Searless, Apoorv Wankhade, Ishank Jaggi, Tom Curran.
Rajasthan Royals: Ajinkya Rahane (C), Ben Stokes, Stuart Binny, Sanju Samson, Jos Buttler, Rahul Tripathi, D Arcy Short, Krishnappa Gowtham, Jofra Archer, Dhawal Kulkarni, Jaydev Unadkat, Ankit Sharma, Anureet Singh, Shreyas Gopal, Prashant Chopra, Sudhesan Midhun, Ben Laughlin, Mahipal Lomror, Aryaman Birla, Jatin Saxena, Dushmantha Chameera, Heinrich Klaasen, Ish Sodhi.
Match starts at 8 PM.
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