By FOX Sports Staff
The forward's new contract sees him stay at the club till 2018 and it follows the signing of similar deals offered to Xavi and Carles Puyol.
Alba believes that the news would be similarly well-received by the club's legion of supporters across the world.
The full-back also expressed his satisfaction that he would not have to come up against the dribbling wizardry of the Argentinean maestro, having previously been confounded by the player during his time at Valencia in the previous season.
"I can't imagine what Messi will be like in 2018, but it's great news for Barça fans that he's staying," Alba told the club website.
"He is the best player in the world and as long as nothing happens, he'll be the best ever. We'll try to make him feel as comfortable here as we can.
"I was once unlucky enough to have to face him as an opponent, but now I'm here I'm delighted to have him as a team-mate.
"I have never seen anybody capable of doing the things that he can do.
"He's also a wonderful person, very down to earth, and that's what those of us who know him appreciate most."
Barca also have a difficult month up ahead as they have La Liga, Copa del Rey and Champions League fixtures to contend with.
Alba is optimistic of achieving the right results and feels tha the team will stay on course to win multiple trophies this season.
"It's going to be a difficult month, with some tough matches, but we have to maintain our intensity in every competition.
"The team is capable of doing that as they have shown in previous seasons.
"We'll be taking things match by match and looking to win them all.
"Before the cup match with Real Madrid we've got league and Champions League games, and they're very important too."