Stuttgart boss Christian Gross believes Lionel Messi can now be compared to Diego Maradona.
Messi, who scored a hat-trick against Valencia at the weekend, continued his fine recent form with two goals as Barcelona beat Stuttgart 4-0 at Camp Nou to secure a 5-1 aggregate victory.
Gross admitted his team "were missing the bravery which served us so well three weeks ago" and felt the defensive midfield performance was not up to standard, but he feels the FIFA World Player of the Year can now be considered alongside the all-time greats.
"They started coming at us so quickly and we tried our best to stay with the pace," he said. "[Messi] is the best player in the world. He's a fantastic talent and it's incredible to think he's only 22. We can now compare Messi with Maradona."
Gross believes the reigning champions may have been bolstered by the fact Real Madrid were knocked out of the competition by Lyon the previous week.
"They were playing in front of their supporters and they are so strong, both individually and collectively," he said. "Maybe the fact Real Madrid were eliminated gave Barcelona extra motivation."
Barca boss Pep Guardiola, meanwhile, has suggested that Messi will take on an increasingly central role for the side in the future.
"Last year we won six titles and he played wide but we need him involved and sometimes he sees more of the ball when he plays more in the centre," he said. "But he is the best, wherever he plays."