Sexton has up until Tuesday to show he can replace Jackson
Johnny Sexton has until Tuesday to prove his fitness for next Saturday's Six Nations clash with France after he took no part in Ireland's team training session yesterday.
The 31-year-old did a sprint routine on the back pitch at Monaghan RFC as part of his rehabilitation from a calf injury as Paddy Jackson ran the backline in front of around 3,000 fans at the open session.
Rob Kearney was also on rehab duty as he did some running behind one goal as he recuperates from his bicep tendon injury, while Conor Murray sat out training due to his workload being managed.
Iain Henderson, Andrew Trimble and Peter O'Mahony were among the 18 who trained fully.
That trio as well as Murray are all in contention to play next week, while Schmidt was upbeat on Sexton and Kearney despite their staying out of harm's way at training.
And the coach said calf-victim Sexton would need to perform in his limited window to displace Jackson after his limited action since November.
"Part of that would probably be based on whether Johnny does put his hand up, how well does he train on Tuesday," he said.
"I think Johnny starts a ripple in the team, very often. He is in a hub position, where a lot of his confidence goes through the team, and Paddy's growing that all the time.
"Johnny did some high-speed running today, he'll do some volume running over the weekend, and then he should be fit to go in and out of training on Monday and then train fully on Tuesday.
"Rob's hitting all his markers. We're probably quietly confident there more than overtly confident, but as long as he keeps going in the direction he's going, we'd hope that he'll take a full part in training on Tuesday."
Simon Zebo stood in for Kearney at training yesterday and is expected to be named at full-back, with Trimble coming on to the wing, if Kearney fails to make it.
Admitting that defeat to Scotland had put his team "under the hammer", New Zealander Schmidt wants the players to show their mettle in the remaining games, at home to the French, away to Wales and against England at the Aviva Stadium on March 18.
"The more experiences you get in that domain I suppose the greater your ability to cope on those situations," Schmidt said.
"We know we are under the hammer. How the players respond when they are under the hammer we will find out a little bit I guess."
Meanwhile, Gregor Townsend reckons Ali Price and Henry Pyrgos are ready to step up and sooth Scotland's pain following the loss of skipper Greig Laidlaw.
Scrum-half Laidlaw has been ruled out of the remainder of the tournament after injuring ankle ligaments in Sunday's defeat to France.
The Gloucester half-back's absence will leave head coach Vern Cotter with a major headache, with the Kiwi increasingly reliant on the 31-year-old's expert decision-making and pin-point goal-kicking.
Price took over at nine when Laidlaw limped off at the Stade de France and will be favourite to start when Wales visit Murrayfield next Saturday.
But his Glasgow colleague Pyrgos could play his way into contention when Glasgow travel across the Irish Sea to face PRO12 rivals Ulster in Belfast today.
"I'm sure Henry is firmly in their thoughts," said Warriors boss Townsend, who takes over the national team this summer. "He's been out injured but played well last week against Scarlets.
"He's our captain so he will have lots of involvement in the game to prove he's match fit and ready to go.
"Ali has played consistently well this season. He's shown confidence and physically has looked really good."