Barca’s Documentation and Studies Centre and La Vanguardia newspaper conducted a joint study to verify the number of official goals scored by Rodriguez in the 1950s.
The study showed he had scored three less than previously thought, Barca said in a statement on their website (www.fcbarcelona.com).
World Player of the Year Messi, who has 51 goals in all competitions this season, could overhaul the record when Barca host Granada in La Liga later on Tuesday.
The 24-year-old is in his eighth season with Barca.
“After studying all of Cesar’s matches, it has been confirmed that Messi is only one goal behind,” Barca said.
“It’s worth noting that Cesar Rodriguez is the club’s all-time top goalscorer in official matches, but the absolute record belongs to Paulino Alcantara, who scored 369 goals in 357 official and friendly matches.”