But the Lions star - who played in all three Tests against Australia in the victorious 2013 tour - has been named in Ireland's starting XV to face France on Saturday.
Joining him back on the field will be fellow Lions Sean O'Brien and Jamie Heaslip, but Schmidt is keen to see how Sexton gets on.
"He's done plenty of contact this week and he's primed and ready to go.
"I think he's feeling very fresh. Sometimes the reverse can happen when you do a lot of contact and you feel very beaten up."