The Everton full-back was one of the positives from Wednesday's dismal friendly defeat to Greece at the Aviva Stadium.
Coleman combined well with Robbie Brady on the right flank in the 1-0 loss, his pace and breaks forward causing the Greeks problems.
"Coleman was fantastic, he was the man of the match," said Trapattoni. "We know him and we have told him he is important to us for the future.
"I have said many times, the midfield of our team is not only the four midfielders; we have two more, the right and left-backs.
"Seamus is fast, he can recover the ball, he has a good personality and at this moment, he has a very good future."
Jose Holebas' first-half strike proved the difference between the sides but Trapattoni was pleased at the amount of chances his side created, and the impact of substitute Wes Hoolahan in the second period.
The Italian said: "He (Hoolahan) was very good. The confirmed the quality we know he has.
"He's a good option maybe if we need to have one striker and at the moment, we have no other players in this position.
"Football is about results, but we had some good situations and three or four of the players showed their personality in this difficult game."
Greece boss Fernando Santos was a happy man too after seeing his side claim a lead, and then defend it doggedly.
He said: "We expected a very competitive game between two good teams and in the first 10 minutes, the Irish team tried to surprise us and they managed to do that.
"But after that 10-minute period we managed to keep the ball more and take the initiative in the game. We had some chances to score and we did score a goal.
"But in the second half, it was a completely different game and we had a very good defensive organisation."