Six Nations 2016: Jonathan Sexton fit for Ireland's opener with Wales

Jonathan Sexton was withdrawn from Leinster's 51-10 Champions Cup defeat by Wasps

Jonathan Sexton is fully fit to start Ireland's Six Nations campaign after another head injury scare, coach Joe Schmidt said on Wednesday.

Sexton, 30, was taken off in Leinster's European Champions Cup loss to Wasps last Saturday, but has passed the required tests to return to training.

"Johnny trained really well yesterday, he is ready to go," said Schmidt.

Ireland and Leinster confirmed that Sexton did not suffer a concussion against Wasps.

The Irish start their attempt to win a third successive championship with a home match against Wales on 7 February.

Sexton missed Ireland's Six Nations opener against Italy last year after being stood down from all rugby for 12 weeks after a series of concussions in a short space of time.

Coach Schmidt has responded to suggestions influential playmaker Sexton should consider quitting the sport to preserve his long-term health.

Schmidt branded those calls "a disappointment", frustrated that observers outside the Ireland camp had questioned expert medical opinion.

"It was this time last year that the problem really arose and he had the break," added Schmidt. "Since that time he hasn't really had too many problems.

"As we're concerned and as far as Johnny's concerned, he is very keen to be ready to go in 11 days' time.

"All we can do is go on the medical opinion, and he had two of the best guys that are around, who made some decisions for him last year and have followed up since then," said Schmidt.

"When they give him the all-clear we've got a lot of trust in them."

Praising Leinster for withdrawing Sexton as a precaution in the weekend's heavy defeat at Wasps, Schmidt said Ireland took head injuries extremely seriously.