Suchith, who hails from Karnataka, was previously part of Mumbai Indians in the IPL.
The 25-year-old spinner has played 13 first-class matches in which he took 45 wickets. He has played 43 T20s as well, taking 37 wickets at an average of 25.54.
Patel had suffered a fracture in his right hand in the game against Kings XI Punjab on April 1 and was ruled out for 3-4 weeks.
As per IPL rules, the replacement player cannot exceed the amount that was being paid to the original player. So the price at which Suchith was acquired by Delhi Capitals cannot be more than Rs 20 lakh as Patel was signed for that amount at the IPL auction.
Delhi Capitals have played seven matches in this edition of the IPL, recording four wins and three losses.
The team is currently placed at the fourth position in the league standings with 8 points and +0.197 as net run-rate.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)