The Uruguay international claimed a double at the Stadium of Light on his return to Barclays Premier League action following his 10-game ban as the Reds ran out 3-1 winners.
Rodgers revealed after the game that Suarez had spent his exile honing his skills to ensure he was ready to make an instant impact.
He said: "Listen, he hasn't been cocooned out of the way and then just come into football.
"I gave him the opportunity to maybe go back to Uruguay for a bit and just come away from it because he is someone who loves football and I knew how much it would hurt him for him not to be playing.
"But he wanted to stay, he wanted to work. He did lots of extra sessions, finishing sessions, conditioning sessions because when he came back, he wanted to be up to speed.
"Of course, you are never going to be totally up to speed, but I think it would be very hard for anyone to say that he wasn't very, very good here, and that's a great credit to him and also our conditioning team, who have put him through his paces for a period of time."
Liverpool were already leading through Daniel Sturridge's 28th-minute opener - a mistimed header from a Steven Gerrard corner which went in off his arm - when Suarez struck for the first time.
Gerrard's superb long ball allowed Sturridge to race past Carlos Cuellar and cross to the far post for the South American to prod home with eight minutes of the first half remaining.
To their credit, Sunderland, who have now taken just a single point from their opening six league games, made a fist of it and gave themselves hope when Emanuele Giaccherini pounced after Simon Mignolet failed to hold Ki Sung-yueng's 52nd-minute shot.
But Suarez made sure at the death when he exchanged passes with Sturridge and steered a left-footed shot past goalkeeper Keiren Westwood.