The Sweden international left Barcelona for AC Milan after only one season in the summer of 2010, and much has since been said about his troublesome relationship with Guardiola.
Nevertheless, the former Spain international had nothing but positive words for Ibrahimovic at his press conference ahead of the first leg of their Champions League quarter-final with the Rossoneri that will see the Milan striker line up against his former team-mates.
"Ibrahimovic was a very important player for us. He helped us a lot and his first six months were excellent. Part of that Liga title we won is his," Guardiola mused.
The Barca coach then went on to stress that Milan will prove to be a tough opponent in Wednesday's European clash.
"San Siro is one of the greatest stadiums in the world. When this stadium shouts, it really shouts. To come here and play is always an honour.
"I'm sure we'll see a great game of football tomorrow. We'll have to be prepared for the difficult moments we'll go through.
"How will we play tomorrow? With seven defenders, hanging on the crossbar ... No, I think our style is well known."
Guardiola refused to look too far ahead as he stressed that an eventual treble is still far away, and a lot can happen in the upcoming weeks.
"Treble still possible? I don't look further than the next game. If we lose tomorrow and on Saturday, that's two trophies gone.
"We'll have to prove our worth again. The objective is to stay motivated after all we've won, to compete until the end."
Wednesday evening's match at San Siro kicks off at 20.45CET.
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