Ahead of the trip to play Falkirk on Sunday, Greece international Samaras said: "When we played against them in the second or third game of the season and won 1-0, it was a really tough game.
"They are a good team but I don't know if they can stay there.
"We see a lot of teams who have a good start and for the first six months they are doing well, but they blow up because us and Rangers have the quality to stay there until the end.
"But I hope they are good enough to challenge until the end of the season because it would be a nice surprise, like it was when Hearts did it a few years ago."
Samaras, who was praised by Mowbray for his performance in the goalless draw against Hamburg in their Europa League clash in Germany on Thursday night, insists he will continue to seek improvement.
He said: "I think I had a good game but I have more to give to my club, my team-mates and my manager as well.
"I am never happy with my performance.
"After every game I go home and try to watch the game again, to see the good points and bad points and try to fix my mistakes.
"I just focus on my football and nothing else. I don't listen to anyone, just my girlfriend and team-mates and I have always done that.
"I am really happy in Glasgow, really happy with the team and happy that I have signed for this club. This is my third season and I am really excited about that."
Celtic face a Falkirk side whose problems intensified this week after slipping four points adrift at the foot of the SPL.
Jackie McNamara and Kjartan Finnbogason were both added to Eddie May's injury list while the prognosis on Burton O'Brien's stomach muscle injury is a two-month lay-off.
May, still looking for his first SPL win, said: "It comes at a difficult time, with Jackie missing for six weeks, Burton O'Brien for eight, Finnbogason for three and Tam Scobbie has still got another six to go.
"We're very restricted in terms of players we can put on the park.
"But it gives people an opportunity who have been here a number of years who maybe think they should have been playing. They can prove they should be playing in the Premier League."
Falkirk lost 4-0 to Celtic in the Co-operative Insurance Cup earlier this season and May has called on his men to make life more difficult for Mowbray's side.
"We have to make sure we're more physical, more in their faces and try to be more aggressive with the ball rather than being negative," he said.