Irish captain Caelan Doris is fit and will face France, handing a massive boost to Ireland ahead of their potential Six Nations title decider in Dublin on Saturday.

The 26-year-old No 8, who missed the win over Wales last month owing to a knee injury, will win his 50th cap and is one of four changes to the starting XV from the Welsh match.

Fullback Hugo Keenan returns, as does prop Finlay Bealham, who was a replacement against the Welsh, and Bundee Aki comes in to partner Robbie Henshaw in the centres for the suspended Garry Ringrose.

"Caelan has done incredibly well to get back to full fitness," Ireland's interim head coach Simon Easterby told reporters on Thursday.

"It says a lot about him that he has done as many other players might not have been able to do that in such a short space of time."

Jamie Osborne, who stood in for Keenan against Wales, moves to the wing as Mack Hansen has a thigh injury.

Easterby said Osborne's versatility earned him the nod ahead of an out-and-out winger such as Calvin Nash.

"We felt it was right to give him (Osborne) the right wing as it gives us coverage across the backs due to his versatility," said Easterby.

"Mack (Hansen) was touch and go, but he was comfortable with the call."

Sam Prendergast and Jamison Gibson-Park, who have been outstanding thus far, will form the half-back partnership.

Jack Conan, who started the Wales game instead of the injured Doris, has also recovered from a lower back problem and will be on the bench.

Like Bealham and Doris, Conan is set for his 50th Test appearance. (AFP)