Former Indian wicketkeeper Farokh Engineer launched a scathing attack on the out-of-form Karun Nair ahead of the fourth Test against England at Manchester, starting July 23. The 33-year-old returned to the Indian Test side after a seven-year absence on the back of stellar performances in domestic cricket.However, Nair has struggled to produce big scores in the first three Tests against England, averaging under 22 after six innings. The right-hander started at No. 6 in the series opener at Leeds before batting at No. 3 in the last two matches at Edgbaston and Lord's.Yet, despite reaching double figures in five of the six innings, Nair hasn't crossed 40.Talking about the Vidarbha batter's struggles in the series in a conversation with TOI, Engineer said:"Karun Nair has been getting brilliant 20s and 30s. He's (Nair) scored beautiful 30 runs, beautiful cover drives and all that. But a beautiful 30 is not expected from a No. 3. You've got to get a not-so-beautiful 100. You need runs on the board. You need (to score) bigger. The expectation should be much higher."Nair's struggles with the bat have proved costly as India trail the best-of-five series 1-2, following a heartbreaking 22-run loss in the third Test at Lord's."If he's good, play him to win this Test match" - Farokh Engineer on Sai Sudharsan replacing Karun NairFarokh Engineer urged the Indian management not to consider age a factor and pick Sai Sudharsan to bat at No. 3 if he warrants a place on merit. The 23-year-old debuted in Tests in the series opener before being dropped for the next two Tests.Sai failed to capitalize on his opportunity to bat at No. 3, scoring 0 and 30 in the Leeds encounter."We should pick the best XI. I haven't seen much of Sai Sudharsan. You've got to pick the best player for the time being. Who's going to give you maximum? You are playing for your country. Your reputation is at stake. So, I would say, forget the age. If he's good, play him to win this Test match," said Engineer (via the aforementioned source).Apart from Sai Sudharsan and Karun Nair, India also have Dhruv Jurel and Abhimanyu Easwaran in the reserves to choose from for the crucial No. 3 spot in the upcoming Manchester Test.