Like German fans before them (and Bosnia fans before the Germans), Denmark supporters chanted Lionel Messi's name at Cristiano Ronaldo during their 3-2 Group B loss to Portugal. Though Ronaldo's poor performance seemed to have far more to do with his own mental blocks than anything coming from the stands, either the chants or the post-match questions about them pinched at his frustrations and prompted Cristiano to defy his usual talking points and compare himself to Messi.
"You know where [Messi] was at this time [last year]? Do you know? He was being eliminated in the Copa America, in his own country," Ronaldo said at the post-game press conference. "I think that's worse, no?"
While Messi and host nation Argentina did struggle at Copa America last July and fail to live up to expectations themselves, Ronaldo seems to have forgotten that Argentina went undefeated in the group stage (one win, two draws) and actually did advanced to the quarterfinals, where they were knocked out by eventual champions Uruguay. In fairness, Messi also struggled to score, as Ronaldo has in this tournament.
All that aside, this really shouldn't even be a comparison. These are two entirely separate tournaments. Criticism of Ronaldo's performance is certainly valid, but neither Messi's name nor his accomplishments have anything to do with the European Championship.