Ryan Giggs hailed Wales' record-breaker Wayne Hennessey as a vital cog in their mean defence after he overtook Neville Southall.
Crystal Palace's Hennessey,33, eclipsed Everton legend Southall as Wales' most capped keeper when he made his 93rd appearance in Sunday's 0-0 draw in Ireland.
It was Wales' fifth successive clean sheet in competitive games.
Hennessey's latest bow leaves him just four games behind Wales' most capped player Chris Gunter, who has made 97 appearances.
Boss Giggs now wants another shut-out when his Welsh side aim to consolidate top spot in Nations League Group B4 in Sofia against Bulgaria this evening.
Giggs said: “Wayne has the experience and is great around the group.
“He organises and makes sure that we are solid at the back.
“We need to keep that up.
“We need to carry on the momentum we have defensively and improve going forward.
“I always feel that we need to get the defensive aspect as we do have players who can hurt teams.
“It is always about getting the balance. You don’t want to give chances away.”
But record-scorer Gareth Bale is missing again tonight as he continues to work on his fitness at new club Spurs.
David Brooks is also out injured along with Juventus midfielder Aaron Ramsey.
While influential targetman Kieffer Moore is suspended after his latest booking in the Republic of Ireland.
Giggs must try to get the right mix between defending well and creating chances after Wales were noticeably shot-shy in the the drab draw in Dublin.
He added: “I am happy with the way we set up defensively but we need to be a bit better offensively.
“We need to be braver on the ball with more composure and progress up the pitch better than Sunday.
“That is about creating relationships between players whether full back, winger, no.10, centre-forward, midfielder, and that is difficult to get with the turnover of players we get.
“That comes and it will come.”
