Lampard blocked Giroud from leaving in January before convincing him to pen a new year-long deal in May.
"He's a manager who's got some good ideas in the game," he told Onze Mondial.
"He communicates well too, in the sense that he knows what he wants to tell his players. The message goes through well.
"Now, of course, there's a need for time to work, to integrate the new players.
“Either way, I have a good relationship with him, especially after we got to know each other during those three days before the end of the transfer window.
"I was in his office, we were trying to find a solution and I eventually stayed.
"I'm staying another year, and I have a good relationship with him."