"Jadeja is a quick bowler and this is a pitch that's going to turn," Manjrekar said on air for Star Sports as India restricted the Lankans to 264/7 in 50 overs.
Jadeja, playing for the first time this World Cup in place of Yuzvendra Chahal, returned figures of 1/40 in 10 overs. He took the wicket of Kusal Mendis.
"Of the three spinning options India have - Kuldeep Yadav and Chahal have been the game-changers for India in the middle in the last 18 months.
"Come the semi-finals and finals, although he has been one with the higher average, Kuldeep and Chahal get more wickets, and have their average as a result under 30. India are assuming they are going to play England at Edgbaston, a small ground where the ball will turn for the spinners.
"They won't have the heart to play both wrist-spinners especially the way England played those two wrist-spinners in the last game so I see Jadeja as a good compromise, a good option. He can keep the runs down when the pitch is turning."
"He will be a force.. just have to contend with people like Morgan and Stokes. So Virat Kohli will have to bowl him at the right time as well," Manjrekar added.
Earlier, speaking to , Manjrekar had said on the eve of the Bangladesh game that he still wanted to back Chahal and Kuldeep Yadav despite their poor outing against England. Reacting to this, Jadeja has asked the expert to "learn to respect" people.
"Still i have played twice the number of matches you have played and i m still playing. Learn to respect ppl who have achieved.i have heard enough of your verbal diarrhoea.@sanjaymanjrekar (sic.)," he wrote on Twitter.
Asked if the way both Chahal and Kuldeep went for runs was another pointer that the team could think of playing someone like Ravindra Jadeja, Manjrekar had begged to differ.
"I am not a big fan of bits and pieces players which Jadeja is at this point of his career in 50-overs cricket. In Test matches, he is a pure bowler. But in 50-overs cricket, I would rather have a batsman and a spinner.
"You never actually base your judgements on exceptional results. India losing to England was an exceptional result. Spinners going for runs is exceptional and you have to understand that," he had said.
If Australia beat South Africa in the other game at Manchester, India will remain second in the points table and take on third-placed England in the semi-final. If the Aussies lose and India beat Sri Lanka, Virat Kohli and Co. would topple the Aussies and go to the top of the table, hence facing fourth placed New Zealand in the last-four stage.
( With inputs from IANS )