Martin O'Neill hailed teenager Declan Rice after watching him turn in an assured display on his senior Republic of Ireland debut in Turkey.
The 19-year-old West Ham defender started at the back and later moved into midfield as Ireland lost 1-0 in Antalya, and looked at home in both roles.
O'Neill said: "I thought he did excellently in the game. He's played left-sided centre-half for West Ham, his club, and at this minute I think he's getting accustomed to a number of positions
"I had no hesitation in putting him into the middle of the field. It was a man-of-the-match performance and I thought he was excellent for us.
"Considering it's his debut and he's 19 years of age, it was an impressive performance from an impressive young man."
Rice, who has indicated he is ready to opt for Ireland rather than England, took his introduction to international football in his stride.
He said: "I think there is something in me. I'm composed and I'm a calm player. You're only out there for 90 minutes and you have to give it everything you've got. It's a game of football at the end of the day.
"I'm only 19, but I've had good experiences with West Ham this year and I've tried to take that on to international level tonight.
"I thought I did well for only being 19 years old on the international scene. I was proud of myself and thought I performed well."
At times, Rice demonstrated an enterprise which O'Neill wants to see from his more experienced players as he re-shapes his squad for the challenges ahead.
The manager said: "Declan Rice made one run there, a super run, things opened up and it's great for the confidence to do that. As he gets more comfortable with the ball, he will sometimes, instead of playing it backwards, he will go forwards.
"That's something I have been urging from the senior players."
In truth, Rice was one of few players in a team which also included fellow debutants Scott Hogan and Matt Doherty to shine on a night when the Republic struggled to impose themselves.
Ultimately, they succumbed to Turkey skipper Mehmet Topal's 52nd-minute volley, although Hogan had passed up a chance to give the visitors a first-half lead when he rounded keeper Volkan Babacan, but could not hit the target from a tight angle.
O'Neill said: "From our viewpoint, it was a good game to play in because Turkey demonstrated their ability on the ball.
"We had the best chance in the first half and restricted Turkey to a number of shouts outside the penalty area, and we might have had a penalty.
"We conceded from a set-piece, a corner kick, which is disappointing, but overall considering a number of our players haven't played and we had a system we haven't really played together, I was pleased with a lot of what we did.
"But obviously there's a lot still to work on."