MI pacer Malinga during a practice session at the Wankhede Stadium on Saturday. Pic/Suresh Karkera

Mumbai Indians coach Mahela Jayawardene described today's Indian Premier League opponent Kolkata Knight Riders as a formidable side. "They're a very good opposition. A very formidable unit and an experienced side. They know how to win matches and how to win championships," said Mahela on Saturday.