Already without world record-holder Sachin Tendulkar, India were in danger of losing both regular openers after Sehwag suffered back spasms during the third and final Test against the tourists at Mumbai.
Sehwag finally batted at number seven in the second innings at Mumbai, where England posted a crushing 212-run victory to square the series 1-1 last week despite missing key players.
The hard-hitting batsman, with 4,220 runs in 141 matches, also missed three one-dayers in Pakistan last month due to a shoulder injury.
His opening partner, Tendulkar, has been ruled out of the seven-match series due also to a shoulder problem. Tendulkar is the world's leading run-getter in one-dayers -- 14,146 with a record 39 centuries.
"He (Sehwag) went through the practice drills and did everything that was expected of him. He has looked pretty good so far and he should be fit to play," Indian skipper Rahul Dravid said on the eve of the match.
"But losing Tendulkar is tough. He did a great job for us in Pakistan. It is not only his batting but also his bowling that has been an important part of the team over the years."
Sehwag returns to the squad just when India need an improved performance from their batsmen to tackle Andrew Flintoff's Englishmen in a series they need to win to keep intact an impressive record.
India have not lost the last three one-day series, but their batting pride was severely dented by a disciplined England attack in the Tests. The worst came at Mumbai when they were shot out for 100 in the second innings.
"Our top-order batsmen have not done well in Tests, but they have been performing well in one-dayers," said Dravid on Monday.
"The 2007 World Cup (in the West Indies) is our goal. There is going to be a few ups and downs. But we have a few youngsters who have done well for us recently and the next eight months will provide them the experience."
The Indian captain said he expected stiff resistance from England.
"They are a very good fielding side and they have played very good cricket in the Test series," he admitted.
England captain Flintoff was all praise for his youngsters in the Test series in the absence of senior players.
"Events in Mumbai were fantastic and we are now looking forward to the one-day series," he said.
"Young players have come in and done a great job in the absence of senior cricketers. They have shown the strength of character. We have to perform to our ability and do the basics right."
England began the first Test without regular captain Michael Vaughan, Marcus Trescothick, Simon Jones and Ashley Giles.
They suffered more setbacks losing opener Alastair Cook and fast bowler Steve Harmison for Mumbai, but overcame the odds to stun India with England's first Test win here in 21 years.