The Blaugrana star will extend his deal at the Liga giants until 2018 on Thursday and the Spain left-back heralded his Camp Nou team-mate as being on the road to becoming the greatest footballer of all time.
"I can't imagine what Messi will be like in 2018 but it’s great news for Barca fans that he's staying," Alba told the club's official 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."
Barca are set to play in their first-ever noon kick-off on Sunday and Alba is expected a tough battle against Getafe, despite the home advantage.
"Getafe are a very difficult opponent," he observed. "They’re aggressive, they’ve got quality players and they play good football.
"They’ll make life very difficult for us but I don’t think playing at noon is any excuse. The difficulty is the quality of the opponent."
February will see Tito Vilanova’s side balance Liga duties with Champions League and Copa del Rey commitments and the Spain international accepts that it will not be an easy period for the side.
He added: "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."
Alba also reiterated the statement that numerous Barca stars are coming out with at the moment: Atletico Madrid are the team’s main rivals this season, not Jose Mourinho’s third-placed side.
"It’s Atletico Madrid who are second," he concluded. "People always speak a lot about Barca and Real Madrid, but it is Atletico who are closest behind us and they need to be treated just as seriously."