The former Hibs striker was left out of the Hoops squad for Sunday's 1-0 Scottish Premiership win over St Mirren following his deadline-day move from Wolves.
But Greek international Samaras believes the Scotland international has the quality to make an instant impact.
Speaking ahead of Saturday's William Hill Scottish Cup tie with Aberdeen, he told CelticTV: "Any player of his quality will be good for the team.
"We know him from the past when he played for Hibs. He is a very good player and hopefully he will adapt to life at Celtic and the atmosphere in the dressing room so he can give 100 per cent in his first few games.
"He certainly has the ability to do that. He can play in more than one position which is good as well.
"He's good with the ball, he has great pace and is a good finisher.
"Hopefully everything will go right and he will help that team as soon as possible."