The Northern Irishman had claimed the 21-year-old French striker had been affected by transfer speculation and had kept him on the bench recently but the injury to Leigh Griffiths at the weekend saw him reinstated for the visit of the Gorgie side.
Dembele was involved in the third minute opener from Odsonne Edouard and after Dedryck Boyata made it 2-0 he notched another before the break with Kyle Lafferty’s second-half strike only a consolation for Hearts, as the home side went 14 points clear of Rangers at the top of the Ladbrokes Premiership.
Rodgers said: “We sat down in the week with Moussa and had a chat over a couple of days and in the second day we pulled together some videos of his work and what his strengths are and through everything that has gone on, he maybe has come away a wee bit from what his strengths are.
“So it was really just a case of looking at his game, breaking his game down and highlighting what type of player he is.
“And when he is like that, when he is pressing and playing in the last line and holding the ball up he is very hard to cope with and that was much more like that tonight.”
Charly Musonda, the 21-year-old Chelsea attacker who signed an 18-month loan deal with Celtic on Monday, was given a great reception in the 62nd minute when he took over from James Forrest and showed some good touches.
Rodgers, who hopes to add a goalkeeper and another outfield player to his squad before the transfer window closes on Wednesday – although he was coy about names – said: “It will take a wee bit of time to find the rhythm with team mates but you see his qualities.
“He has that creative imagination to open the game up.
“It was nice of him to feel the crowd and he will be a great addition for us.
“It was a very good performance, both halves.
“We took our chances first half, we didn’t in the second half but overall, an outstanding team performance.”
Hearts had ended the Hoops’ 69-game domestic unbeaten run with a 4-0 home win in December but they were out-gunned at Parkhead.
However, boss Craig Levein, who revealed midfielder Harry Cochrane sustained a neck injury which led to him coming off in the first-half, was pleased by the way his side approached the second period.
He said: “What we pleased me was that we stuck at it.
“Celtic had opportunities in the first-half but it was because of the way we played, we went man for man at times with players high.
“They seemed to score with about every chance.
“Half-time was interesting. Damage limitation or do the same thing? The players were determined to go again in the second-half.
“We had a go again and we did well, got a goal and didn’t lose any more goals and it gives me some heart that we can come back and do a similar thing the next time we are here.”
Uwe Rosler was sacked by Fleetwood following a 3-0 reverse at Doncaster which condemned Town to a seventh straight defeat in all competitions.
Cambridge interim head coach Joe Dunne was pleased with how his side adapted to beat Grimsby 3-1.
Southend manager Chris Powell led the applause for Jason Demetriou after the right-back scored twice in the 3-1 win against Portsmouth at Roots Hall.
Morecambe boss Jim Bentley was the happier manager after Gregg Wylde's 90th-minute strike earned his side a point in their 1-1 draw with Forest Green.
Manager Gareth Ainsworth described Wycombe's 2-0 win at Cheltenham as a thoroughly professional performance.
Skipper Richard Wood scored the winner just before half time as in-form Rotherham pulled off a 1-0 victory at League One leaders Shrewsbury.