Sexton, who will start at fly-half against Wales on Saturday, informed the Irish Rugby Football Union that he would be leaving Leinster at the end of the season, with Racing Metro his expected destination.
Leinster colleague Rob Kearney revealed that Sexton was "upset" by the way negotiations unfolded and did not want to leave Dublin.
It has been reported that Sexton was disappointed not to have been offered parity with Heaslip, but Ireland's new captain denied the issue had affected their relationship.
When asked if there was any tension between himself and Sexton, Heaslip replied: "No, not in the slightest.
"It (France) has always been there, it's not like it's a new ball park. I doubt Jonny's thinking about being a guinea pig for anyone else.
"There hasn't been much chat except a bit of banter and trying to speak French to him.
"Jonny had to weigh up the offers and chose the option he chose. As a club-mate at Leinster and friend it's disappointing to lose him. We're going to miss him.
"It will be an amazing adventure for him and I'm sure he's looking forward to it.
"He's the ultimate professional. He came in on Sunday night and was good to go.....as cranky as ever. The business is done and now he's onto the next challenge."
Ireland have restored centre Brian O'Driscoll, full-back Kearney, hooker Rory Best and openside Sean O'Brien to their starting XV against Wales after the influential quartet missed the autumn through injury.
The exciting Craig Gilroy and Simon Zebo have been named on the wings as Ireland seek to end their three-match losing streak against the Grand Slam champions at the Millennium Stadium on Saturday.
"Wales are the champions, we're going to their back yard and they'll be smarting from their disappointing November, so we know we're fully up against it," coach Declan Kidney said.
"The Six Nations has now become unique in that there is no back door - there are no bonus points or home and away games like there are in the Heineken Cup.
"It's not quite knock-out rugby but if you get off to a good start in your first game, it gives you a great chance to go on and do things."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.
