In September, Krishna suffered a back injury playing for India A on the eve of a three-match Test series against New Zealand A.
The 27-year-old underwent successful back surgery and will require significant time for rehabilitation, ruling him out of the majority of cricketing action this year.
The Royals have acquired the services of Sandeep Sharma for his base price of INR 50 lakhs, and he will join the team with a tally of 114 wickets in 104 innings at an average of 26.3 and an economy rate of 7.3 runs per over in his decade-long IPL career.
The 29-year-old endured a dismal IPL 2022 and managed to scalp only two wickets in five innings, leading to his downfall.
The right-arm pacer is known to swing the ball early in the powerplay and could prove to be a lethal combination with Trent Boult early in the innings.
Rajasthan Royals kickstart their campaign against Sunrisers Hyderabad on Saturday, 2nd April, in an afternoon encounter at the Rajiv Gandhi International Stadium.