Wolves striker Doyle, 29, has not featured for the Republic since the 1-0 friendly defeat against Greece last November.
He was last included in a squad in March and was again left out of manager Trapattoni's selection for Wednesday's friendly against Wales despite Robbie Keane, who has been allowed to remain with Los Angeles Galaxy, and Simon Cox being unavailable to the Italian.
Trapattoni insists the 53-cap forward remains part of his thinking going forward, but acknowledged he needs a move from League One Wolves.
He said: "I have Doyle in my heart. I promise him we will continue to follow him.
"But it is important to look around, with players like Paddy Madden and Simon Cox we can look to the future. We have many strikers.
"If I had called him (Doyle) in for this game, maybe he would be on the bench and not play which would not help his confidence and I have to do what I feel is right."
When asked if a move before the end of the transfer window would be good for the former Reading man, Trapattoni added: "It would be better as he can try and regain confidence.
"Many times I have said to you strikers depend on the support of their team.
"Without the team to give you the ball to score it is impossible.
"Kevin is an intelligent player. I think it is important for him to get another opportunity, whether the money is 20 per cent more or 20 per cent less. It's important to go to a club to play. It depends on his agent."
Trapattoni's squad has been heavily hit by injuries ahead of the friendly contest with the Welsh at Cardiff City Stadium, as the Republic build towards World Cup qualifiers with Sweden and Austria.
Norwich midfielder Pilkington's knee injury comes after three previous occasions when he has had to withdraw from the national squad.
But Trapattoni has no doubt Pilkington wants to represent the Republic and made it clear he does not believe the player has done anything wrong in failing to report to have his injury checked.
He said: ''We have a good relationship with our doctor, he knows many club doctors and with Pilkington I also asked Wes (Hoolahan) and he told me his knee is swollen, he has been having injections and he has pain and I am confident about the professional doctor.
''The doctor is important, he is not a manager, it is a specialist position with a big responsibility.''
Trapattoni also revealed plans to start with Kieren Westwood in goal on Wednesday and is pondering trying out a 4-4-1-1 formation with Jon Walters being utilised out wide.
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- Simon Cox
- Anthony Pilkington