For the former AC Milan and Chelsea forward, Messi can be decisive for the Catalan giants in their quest to end rivals Real Madrid's dominance in the Champions League and secure the trophy for themselves.
In fact, Shevchenko believes that the competition will come down to whether Barcelona's talisman can continue at his current level.
In an interview with 'Mundo Deportivo', the Ukrainian said: "If Messi continues to play like he did on Wednesday, Barca will be European champions this season. This Messi is unstoppable, we've already seen it against Chelsea. Nobody can deny it when he's at this high level".
So far, the Argentine's performances in the Champions League have been outstanding. In eight games he has contributed six goals and two assists, half of which he produced in the Round of 16 tie against the Premier League outfit (three goals and one assist).
Now Messi must bring his magic touch and finish to Italy when Barcelona take on Roma in their quarter-final clash in April, and given his impressive record against Serie A teams, it could be another goalfest.