Ibrahimovic played under the Spaniard at Barcelona for only one season in 2009/2010, but their relationship soured and the striker had to leave for AC Milan.
Both men are now in the Premier League, with Guardiola coach of Manchester City, while the Swede plays for city rivals, Manchester United.
Ibrahimovic said taking on Guardiola’s teams gave him more inspiration, although he insisted it was nothing personal.
“When I play against his team, it’s something that motivates me, it gives me adrenaline,” he told Fox Sports Italia.
“It’s not personal what I have. It’s part of the game.”
Ibrahimovic and Guardiola won the La Liga title in their season at Barca, with the 35-year-old scoring 16 league goals.
Ibrahimovic explained how it all went wrong.
“First he called me every day to have me and from one day to the next I didn’t play anymore,” he said.