Stephen Ferris says he'd like to see Andy Farrell mix things up a bit for the Six Nations visit of France to Dublin on Sunday.

Despite having opportunities to win it, some careless mistakes and poor decision making cost Ireland dearly as they started the campaign with a defeat against Wales in Cardiff last weekend.

Their championship hopes already hang by a thread with no room for another defeat at the Aviva against Les Bleus, who are favourites for both the match and the tournament.

That said, a win for the hosts this weekend would blow the championship wide open.

Speaking on RTÉ's Game On Ferris says that Farrell needs to make some big decisions in his team selection this morning.

"I would like to see him mix it up," said the former Ireland international. "I would like to see him use this Six Nations to give more guys game time.

"His hand might be forced with Johnny Sexton, with Peter O'Mahony.

"Who comes into the back-row? Does Will O'Connor leapfrog (Josh) van der Flier? I know he did well just before the try, but apart from that he didn't offer much more in attack.

"The succession plan, which has been talked about all week after Sexton going off, and Billy Burns making a couple of errors in the latter part of the game.

"These guys need game time before the next Rugby World Cup. They need to experience the big moments in Six Nations matches (and) in summer tours against the top two or three sides in the world.

"Yet they don't seem to be getting much of it.

"I don't think it's just at out-half - it needs to be other positions as well. I expect a few changes."

Sexton leaving the field in Cardiff last Sunday

There has been much talk about Jonathan Sexton's fitness after the number 10 had to come off at the Principality Stadium, having received an accidental knee to the head from Justin Tipuric.

A French doctor was forced to apologise after speculating on the number of concussions the 35-year-old had suffered in his career.

The Dubliner told media earlier this week that he has been following the return to play protocols following his HIA assessment in the Welsh capital, and that he has passed them all so far.

But Ferris believes that it's a quick turnaround for Sexton to take to the pitch this weekend.

"It's never a good look when the captain of Ireland goes down, and in my own opinion it looked like he was knocked out.

"He might not have been fully knocked out, I'm not 100% sure, and I can't clarify that, but he got up and he  walked off the pitch. That's a good thing to see.

"I was speaking to someone in the boxing world and I put it to him that if someone was knocked out in the ring, would he put them back in for another fight the following week.

"The answer is no.

"There are rules in place. You can't get back into the ring for 28 days. Even if you get knocked down with a body shot and you can't get up - you're counted out - it's 14 days.

"It seems strange that if you get knocked out in an international rugby match you can take to the pitch the following week.

"Was he knocked out? I don't know, but it's another bang to the head (and) he's got a history of concussions."

Follow Ireland v France (kick-off 3pm) on Sunday via our live blog on RTE.ie and the RTÉ News app or listen live on RTÉ Radio 1's Sunday Sport. Highlights on Against the Head, Monday at 8pm on RTÉ2 and RTÉ Player.