John McEnroe is refusing to back down on statements he made about how 23-time Grand Slam winner Serena Williams’ would fare on the men’s circuit.

McEnroe, a 7-time Grand Slam winner, sparked controversy during a Sunday, June 25, NPR interview when he said Williams would “be, like, 700 in the world” if she played on the men’s tour.

“I respect Serena, very much so,” McEnroe tells CBS This Morning Tuesday, June 27, before explaining why he called Williams “the greatest female player in the world” in his book, “But Seriously,” rather than simply the “greatest player in the world.

When co-host, Norah O’Donnell asked McEnroe if he would like to apologize, he said, “No.”

“Why don’t you combine … Just solve the problem – I’m sure the men would be all for this – the men and women play together and then we don’t have to guess,” he says.

McEnroe maintained that he didn’t know controversy would follow his remark, which Williams responded to Monday on Twitter by saying, “I adore and respect you but please please keep me out of your statements that are not factually based.”

“Respect me and my privacy as I’m trying to have a baby,” she added in a subsequent tweet.

“I don’t want anything to go wrong with Serena because she’s pregnant,” McEnroe says. “I don’t want to upset her or whatever it was. She’s – I think she was doing a tongue-in-cheek as well.”

McEnroe added that he “can’t even believe we’re talking about it,” but co-host Gayle King pressed him on the issue.

“I think it sort of belittles what women do on the tennis court,” she says before asking McEnroe where he would rank himself.

“I would be, currently, about 1200 in the world,” he says, adding, “I never wanted to play Serena.”