Giovanni Trapattoni has warned Darron Gibson his space in the Republic of Ireland midfield will not be left open should the Everton player continue to refuse to play.
The Republic begin their 2014 World Cup qualifying campaign on Friday against Kazakhstan, a game Gibson has made himself unavailable for.
Trapattoni has selection problems with Keith Andrews and Paul Green ruled out and he was hoping to slot Gibson in to his midfield, but the 24-year-old has refused the call-up.
Gibson was frustrated with Trapattoni when he did not make it off the bench during the country's dismal Euro 2012 campaign and states this as his reason for not playing now.
"I spoke with Gibson for a long time," Trapattoni said.
"He explained to me that he was disappointed. I understood but I said to him that we were all disappointed after the defeats in the Euro campaign, but I said that this is a time for a new opportunity."
The 73-year-old Republic boss says he respects Gibson's decision but insists his side can do without him.
"In the past we were frightened about missing players, but now we already have a squad," Trapattoni added.
"We have been watching also new players, maybe we will discover a new Irish player. He has to decide whether he wants to play or not."
Trapattoni defended his decision to overlook Gibson for the entire Euro 2012 campaign.
He claims that playing the midfielder against Italy in the final group game would have looked as though he was making changes to favour his home nation.
He said: "It was impossible to change.
"With 20 minutes to go in our match Italy could have gone out and Croatia could qualify. If we changed it and we lost it would have looked like I favoured Italy."