On Wednesday lunchtime, the Blues announced that they had agreed a five-year contract with the highly-rated teenager.
The announcement brought to an end a prolonged saga that initially saw the 18-year-old prevented from playing any competitive football for the club unless he extended his deal.
Having completed the 90 minutes against Astana in the Conference League last week, Acheampong is now expected to feature again when the West Londoners face Shamrock Rovers in the same competition on Thursday.
Maresca reveals Acheampong impact
Speaking at a press conference ahead of that fixture, Maresca was quizzed on the situation that evolved with Acheampong, acknowledging that he immediately took a liking to the starlet.
The Italian told reporters: ""Very, very happy. With Josh, it has been quite clear. He was with us in pre-season. I didn't know him personally, but after two or three days that he was with us, he impressed me.
"Since the pre-season, I have been trying to understand the situation in terms of contract and this kind of thing, and finally, the club found an agreement with him.
"We are all happy because we are all convinced and sure that Josh can be a great player for this club."
What is the next step for Acheampong?
A major reason as to why contract negotiations were drawn out was due to Acheampong's representatives being unsure over whether he will earn suitable game time at Stamford Bridge.
Prior to last week's outing in Kazakhstan, Acheampong had been given just 32 minutes across games with Tottenham Hotspur and Barrow.
Nevertheless, it appears that he can expect more chances going forward with Maresca revealing that he would not like to loan Acheampong to another club.
He added: "My personal opinion is that he has to stay close to us."
With Reece James currently sidelined through injury, it remains to be seen whether Acheampong will be viewed as deputy to Malo Gusto for Premier League fixtures in his absence.
Written by
Darren Plant