Sexton played with Racing 92 in France for two seasons
Ireland captain Rory Best has said that fly-half Jonathan Sexton "will have a big role" against France on Saturday.
Best was speaking in the Stade de France after Friday's Captain's Run. Sexton played for two seasons in Paris with Racing 92 before returning to Leinster last summer. France's matchday squad has five players from Racing included in the 23.
"With the amount of emphasis (Sexton) put on everyone knowing the individual profiles of the French players, if Johnny knows one of the players personally and somebody asked him about it, Johnny is always giving of his time with information. From our point of view, the pressure is on each player. You can't rely on Johnny because he has played in France, to help us with the profiles. We got to know them ourselves."
Ireland have not lost in Paris since 2010 in the Six Nations. The last trip to Paris resulted in a Six Nations triumph in 2014 as Sexton scored 17 points including two tries in Ireland's 22-20 win.