Boateng has played alongside some of the greatest footballers, and Ibrahimovic stands out for the former Ghana international
Ibrahimovic and Boateng were team-mates at AC Milan, with the pair helping the Serie A giant win the 2010-2011 Scudetto.
Asked to name the best player he has played with, Boateng told Barcelona TV in a Q&A: "Zlatan Ibrahimovic."
Boateng's answer came as a surprise, given he plays with five-time Ballon d'Or winner and Barca's all-time leading goalscorer Messi.
The 32 year-old, who completed a shock loan move to Barca in January, was forced to dismiss suggestions of a past allegiance to Real Madrid and Cristiano Ronaldo after his Camp Nou arrival.
Boateng lauded Messi as the best player "in this world and every world" during his official presentation after past quotes declaring himself a Madrid fan and describing Ronaldo as the world's best resurfaced.
Messi has scored 39 goals in all competitions this season, while Boateng has only made three appearances since swapping Sassuolo for Barca on loan.