Fletcher coached England for eight years -- from 1999 to 2007 -- and was earlier this week appointed India's coach to succeed South African Gary Kirsten.
Swann, who fell out with Fletcher soon after his debut in 2000, said the Zimbabwean might think he knows the entire English team very well but he hardly understands quite a few players of the side.
"Fletcher knows a few of our players better than some other coaches would," Swann told the 'Daily Telegraph'.
"But there's a hell of a lot of our team he doesn't know at all. I think that will work to our advantage, because he might be trying to double guess us a little bit and come a cropper," he said.
Swann played his first Test almost eight years after his international debut due to his erratic behaviour which led to the fallout with Fletcher.
"If I was a coach 10 years ago, I don't think I would have picked me, and I wouldn't have particularly liked me being on that tour," Swann said.
"If you're my sort of character, you soon become quite irksome to the people around you if you're not backing your talk up on the field.
"I was just a young upstart tourist, and it was a good job I didn't play because I wasn't good enough. I'd probably have been found out and cast aside for good, and never been given my eventual second chance," he added.
Swann said whatever the result of the July series, it would be an interesting battle between the world's number one Test side and the reigning Ashes champions.
"It's nice for him to come back to England, because he's got a fine record with the England team," Swann said.
"Now he will get a chance to pit his wits against this new England side during the summer. Technically, though, I don't think it helps him much to know a few of our players, because there's so much footage available that you can work anybody out," he added.
"I think we will give India a very good run for their money, if not beat them."
