Stephen Kenny says Michael Obafemi opted out of the latest Republic of Ireland squad due to the threat of injury.
The forward - who has been in good form for Swansea City - has not been included in the 25-man squad for the games against Belgium and Lithuania.
Reports had emerged that Obafemi rejected an under-21 call up in the hope of a senior one, but this too was dismissed by Kenny.
"Michael was never in the picture to be in this Under-21s squad, so I'm not sure how that discussion occurred,” the manager explained.
“It's been a heavy load for Michael,” said Kenny.
“I think there's a degree of anxiety around Michael himself about being injured.
"He's never had what he's had before, a run of games, and he feels his load is so heavy, he's concerned about re-injuring coming into the international team and trying to train every day and play and play again.
“He feels he needs to spend time with the physios to make sure he can continue in the vein of form."
Kenny says he has been in conversation with Obafemi in recent weeks, and he has reiterated his commitment to the national team.
Other notable absentees include Aaron Connolly and Jamie McGrath.
Kenny says that Connolly is struggling with a heel problem - but McGrath's exclusion was due to poor form.
“I just haven’t selected Jamie.
“It’s a tough call as he’s been really excellent for us. But his move hasn’t gone to plan for him, he’s not been featuring for Wigan and even been omitted from the squad on occasions.
“It’s not really his problem. He was in great form and doing well, but came into a team that was consistently winning and they just haven’t made the changes and he’s paid the price for that."
Ireland play Belgium on Saturday week, before hosting Lithuania three days later.