England captain Dylan Hartley is fit to return for club side Northampton Saints after five months out with concussion.
The 32-year-old hooker is in the side to face Glasgow in a pre-season friendly at Franklin's Gardens on Friday, and said he was "confident I will play rugby until I am 50".
The concussion he suffered in March's Six Nations loss against Ireland was his third such injury.
"I sought good advice and I trusted what they said," said Hartley.
"I had no concerns. I surrounded myself with the right advice and here I am - ready to play.
"At the time it was disappointing because you want to be involved in everything. You don't want to miss games.
"But once the decision had been made for me and we agreed on it, I had made peace with that.
"As soon as I took my foot off the gas and stopped trying to make it back every week, which I was trying to do, I felt myself instantly get better.
"Removing those kind of pressures has worked. I have had a good pre-season with the team and I am in a good place to compete for a spot in the next fortnight."
Hartley, who has 93 caps for England, took part in a three-day training camp with the national team in Teddington this month.
Northampton's opening game of the Premiership season is away at Gloucester on 1 September.