Messi ran amok at Wembley Stadium, slicing Spurs apart with incisive passes from deep, such as the one that allowed Philippe Coutinho to open the scoring.
And was as dangerous as ever in front of goal, firing in the Catalan side's final two goals to end their winless run of three games.
"Messi eats at his own table, he plays on another level to the rest," Barca defender Alba told reporters, as quoted by ESPN.
"When Leo goes on a run, all the rest of us can do is grit our teeth. He is the best in the world and he makes all of us a little bit better."
Messi was a surprise exclusion from the three nominees at FIFA's The Best awards ceremony last week in London - where Real Madrid's Luka Modric was crowned Player of the Year ahead of Mohamed Salah and Cristiano Ronaldo.
"For me 'The Best' is a lie," said Alba.
Rakitic, the scorer of the Blaugrana's second goal at Wembley also paid homage to the Argentine.
"With respect to the other players, Messi is unique," he added. "Sometimes a player has a great season like Modric did, but we all know Messi is different."