"Messi has said many times that he wants to retire here and I have no doubt that he will re-sign," Bartomeu said in an interview published by Barcelona's sports newspaper Mundo Deportivo.
The 33-year-old is currently contracted until the end of next season with Barcelona holding talks with the ace Argentina forward about an extension.
There is speculation that record six-time Ballon d'Or winner Messi is unhappy with the club's leadership.
Speaking about Neymar returning to the Catalan giants from French champions Paris Saint-Germain, Bartomeu said: "Now we are making decisions and the players, if they do not come as part of a player exchange programme, it is very difficult for them to come."
Earlier, former Barcelona midfielder Luis Garcia had said that Messi can easily continue playing till 2025.
"Why not? The way he is playing, adapting his style to the game, is impressive. Every year he shows us something different but keeps up the same amount of goals, assists," Garcia, who played for Barcelona in the 2003-2004 season, said during a video conference facilitated by LaLiga.
"Even getting more every year! He's adapting, he doesn't spend so much time up front because he knows it's harder, so he drops a little more. He shows why he's so intelligent. He adapts his game to what the team needs in every match. I could see him playing in 2025, easily!" added the former Atletico Madrid and Liverpool winger.
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