Jedinak is also the skipper of Australia and will be absent from club duty during January as the Socceroos aim to win the tournament for the first time.
The 30-year-old played a key role in Palace's survival last term and has already weighed in with two goals this season.
Warnock hopes Jedinak can add more goals to his game this season but is disappointed Palace will be without their leader.
"We will miss him," Warnock is quoted as saying in the Evening Standard.
"He is the leader of the camp. Everything on and off the field revolves around him.
"There is the Africa Cup of Nations at about the same time, too, so it will be difficult for a lot of teams in the Premier League in January and February.
"Mile has been able to push forward more than usual this season, too, and I think he can score more goals."
