Republic of Ireland skipper Robbie Keane was on the training pitch in Malahide with his team-mates for the first time Tuesday morning.
The 31-year-old striker flew in from Los Angeles Monday afternoon and was among the squad for the early part of first session of the day.
LA Galaxy forward Keane, who is recovering from a minor hamstring strain, left early to return to the team hotel, but Trapattoni will be delighted to finally have him among the fold.
However, goalkeeper Shay Given has handed Republic boss Giovanni Trapattoni a scare after undergoing a scan on a knee injury.
The 121-times-capped goalkeeper was sent for tests after hurting the knee in training on Monday but is now only expected to sit out two to three days of this week's preparations in Malahide.
A spokesman for the Football Association of Ireland said: "Shay Given picked up a minor knee injury in training.
"After undergoing a scan, it was concluded that Shay should sit out training for the next 2-3 days for precautionary measures."
The Republic face Bosnia and Herzegovina in a friendly at the Aviva Stadium on Saturday afternoon before heading off for their pre-Euro 2012 training camp in Italy the following day.
However, while 36-year-old Given may yet appear in that game, defender John O'Shea is unlikely to as he continues to battle an ankle injury.
The 31-year-old Sunderland man has not trained fully since joining up with his team-mates as a result of the problem he aggravated in the Black Cats' final game of the season against former club Manchester United.
However, Trapattoni remains confident he will be fit for the tournament, which gets under way against Croatia in Poznan on June 10.
The spokesman said: "Giovanni Trapattoni has also decided that John O'Shea may not partake in Saturday's game against Bosnia for precautionary measures, but has confirmed that John will be fit in time for Euro 2012.
"John is undergoing rehabilitative treatment this week on his ankle."
