India great Farokh Engineer believes the "true test" of Virat Kohli's current side will come when they tour England next year.
Under the captaincy of star batsman Kohli, India have risen to the top of the world Test rankings.
But much of their success has come in home or sub-continent conditions, with their recent 3-0 Test series win in Sri Lanka being a case in point.
Engineer, an outstanding wicketkeeper-batsman for both India and English county Lancashire, said the real worth of Kohli's men would be judged far away from home.
"The present Indian team are very good indeed," Engineer said at Lancashire's Old Trafford headquarters on Tuesday shortly before England played West Indies in a one-day international at the Manchester ground.
"Virat Kohli is an excellent captain, MS Dhoni is looking fitter than ever, Ravichandran Ashwin is one of the great off-spinners, (Ravi) Jadeja, we've got a very good team, Murali Vijay, the opening batsman," Engineer added.
"They have been scoring a lot of runs against Sri Lanka, but the true test will be when they come to England.
"Don't get carried away by the performance against Sri Lanka, against Australia we are doing pretty well, but that's in India again."
The 79-year-old Engineer, a veteran of 46 Tests for India from 1961-75, said next year's five-match series in England would "sort the men from the boys".
"India's real test comes when they go abroad, especially England. England is the true test for any cricketer and Indian cricketers are no exception," he said.
"You need a real sound technique to play in England where the ball moves about a lot more, both in the air and off the pitch.
"Your technique is really stretched to the limit -- it sorts the men out from the boys."
Only three times in their history have India won Test series in England, most recently in 2007.
But Engineer was in at the finish of their ground-breaking victory at The Oval in 1971 - India's maiden Test win on English soil seeing them to a 1-0 win in a three-match series following two draws.
"Yes indeed 1971 in England was a great moment," said Engineer.
"I got runs in both innings (59 and 28 not out) and dismissals as well, but a guy called Abid Ali came in and took all the limelight.
"We had four runs to get I think.
"I said to him: 'Abid, after you there's only Bishen Bedi and (Bhagwat) Chandrasekhar and with due respect they don't know which side of the bat to hold'.
"He said: "OK, OK". What does he do first ball? He just charges down the pitch - I think Alan Knott missed a reasonably easy stumping," Engineer recalled.
"We needed three runs because I took a single and regretted it.
"So what does he do now? He charges down the wicket, gets a top edge, four over the slips, and the next thing I see he's being carried off by people for a not-out four - and I've stuck in there!
"But it was a great moment, a sweet victory for India because India had never before won a Test match in England."