The City boss is currently sidelined following surgery last week but is expected to return after the forthcoming international break.
Lillo oversaw the treble winners' Premier League trip to Sheffield United last week and will remain in charge for Saturday's match against Fulham.
"I speak very regularly with him," Lillo told a press conference.
"He's much better and things are taking place in the way that they should do. All of us are delighted and are really looking forward to him getting back."
Lillo stayed in touch with Guardiola during City's win at Bramall Lane last Sunday and has kept in contact with the Spaniard ahead of Fulham's visit to the Etihad Stadium.
"It's the same as the previous game," said Lillo. "With Pep there would be more energy but we're in contact with him all the time.
"We share our responsibilities well, we have our roles very well defined by him and we will continue on the right path but he obviously continues to have input.
"We're not quite finished in our preparation for the game."
City defender John Stones is nearing a return to action following a thigh injury, with Lillo also upbeat about the health of Phil Foden and Manuel Akanji.
"Phil is completely recovered from his illness, Manu's problem was more for prevention rather than anything serious," he said. "He's more or less there and John is more or less there as well."
