Injury rules out international chance.
U's Physio Tony Flynn told the official website: "Louis came back to us earlier this week, having suffered an injury to his ankle whilst training with the Irish squad."
Although it was a blow for Louis to miss out on the games in Scandinavia, fortunately the injury isn't a major one.
But an injury in training ahead of the squad flying out from Ireland has seen him return to north Essex for treatment.
The U's youngster was named in the Republic squad for games in Sweden this week, against Hungary on Thursday and the hosts on Saturday. Louis Dunne will miss out on two Republic of Ireland U18s internationals.
Future chances were on his mind as he said: "I was massively disappointed to miss out but the coaches reassured me that they would keep an eye on me."
"I felt I had made a decent impression in the two training sessions before I picked up the injury and had really enjoyed it."
"I had worked with the Manager at U16s level before and in a good chat we had, he told me he thought I had become a stronger player since then."