Tiago came out of international retirement last month, returning the Portugal set-up after four years away to feature in a 2-1 friendly defeat to France and a 1-0 victory over Denmark in Euro 2016 qualifying.
The 33-year-old was joined in making a return to the fold by Monaco defender Ricardo Carvalho, who fell out with previous coach Paulo Bento in 2011.
Jose Bosingwa is the latest veteran to come out of the international wilderness under new boss Fernando Santos, and Tiago believes their experience could prove invaluable during the campaign to reach France.
"It's a joy to have players of my generation back because we've had many good times together," he said. "For younger players themselves it can also turn out to be important, because they see us as references.
"We have more weight in the squad and this can help them to not feel so much pressure.
"This experience will be important in this kind of game, which will be complicated and we know that we cannot relax.
"We know that the stadium will be full and the Portuguese will expect us to have the game won early. I think the more experienced players can better cope with this pressure."
Portugal bounced back from a shock 1-0 defeat to Albania by beating Denmark last time out, and will be confident of picking up three points against Armenia in Faro on Friday.
Denmark and Albania are currently tied on four points at the top of Group I, with Portugal a point further back in third.
Armenia, meanwhile, are seeking their first victory of the campaign, but will not have history on their side in Friday's match having lost on their last two visits to Portugal.
Visiting hopes will rest largely on prized asset Henrikh Mkhitaryan, while Portugal could hand a debut to 30-year-old Southampton defender Jose Fonte following a promising start to the Premier League season.
Braga's Tiago Gomes and Adrien Silva of Sporting could also be in line for a first international appearance.
