Aitor Karanka hailed the revival of Victor Valdes after the goalkeeper helped Middlesbrough snatch a 1-1 draw at Manchester City.
Valdes held City's incessant attack at bay, save for Sergio Aguero's 150th goal for the club, until Marten de Roon fired home a stoppage-time header to earn a point for the Teessiders at Etihad Stadium.
Having lifted the European Championship and World Cup with Spain, as well as multiple LaLiga and Champions League titles at Barcelona, Valdes has enjoyed regular action this season for the first time since a serious knee injury prematurely ended his Camp Nou career in March 2014.
Having established himself as Karanka's first choice ahead of Brad Guzan and Dimi Konstantopoulos, Valdes is making a strong impression on the Premier League, after a failed stint with Manchester United.
Karanka said: "He's really important and I'm really pleased for him because his first games weren't really good and as a keeper you need a lot of confidence.
"I try to transmit all my confidence to him and now he's showing how good he is.
"I said two, three weeks ago he's not just here because he's an amazing goalkeeper, he's here because he's a leader in the changing room, he's an experienced player and I said always he was going to help us a lot."
Karanka acknowledged Valdes is unlikely to return to his absolute best, but the Spanish veteran remains a key member of his Boro squad.
"Today he did three amazing saves," Karanka added.
"It was the same against Arsenal, last Saturday against Bournemouth he did two or three.
"But it's not pressure for him because when I signed him I told him he's not the same keeper as he was at Barcelona because if he had been in that level he wouldn't have been here.
"He's with us because he had problems in the past but the main thing for me is to keep him happy, because he's an amazing keeper on the pitch and important player for us in the changing room."
