The Frenchman, 32, made more than 200 appearances for Arsenal in two spells but was a free agent this summer, enabling him to sign a one-year deal with Palace.
He will travel with the squad for Saturday's Premier League fixture at Middlesbrough.
"Whenever I watched Arsenal when Mathieu was in the side, he always gave them that winning mentality, that will to get the team over the line," Pardew told a news conference.
"That mentality is what I want to add here. I bought him not just as a player but as a figurehead.
"He'll be pushing the likes of Joe Ledley and Yohan Cabaye -- and I think he will push them very, very hard."
Pardew also confirmed that on-loan French striker Loic Remy faces seven or eight weeks out after suffering a thigh injury in training.
Remy, who joined on a season-long loan during the transfer window, is expected to return to parent club Chelsea to recover.
"The figures that are being pushed around are about right, seven or eight weeks, something like that," Pardew said.
(Reporting by Martyn Herman; editing by Sudipto Ganguly)
