The 25-year-old Spanish forward, who was signed from Celta Vigo for £7.7m last month, played the second half for the Reds at Deepdale and marked his debut by curling home the final goal from long range with his left foot.
"Iago works hard; he's got a trick in and around the box and he excites supporters," said Rodgers.
"He's a good guy and he works very hard for the supporters. He drifts well in between the lines and always wants to receive the ball but what I like is that he wants to score goals.
"He's looking to create and combine or go solo by himself and get a shot in. His goal was a terrific strike."
Rodgers' other three new signings also played and, although goalkeeper Simon Mignolet and Kolo Toure had little to do, midfielder Luis Alberto set up Raheem Sterling for the third goal after Philippe Coutinho's penalty and Jordon Ibe's low strike had given Liverpool a 2-0 half-time lead.
"The players have been back for 11 days now and I thought their work-rate, quality and intensity in the game was very good so I'm very pleased," added Rodgers.
"Mignolet was very confident and very composed. He had a great day today. Everything he did, he did it well. And he's already integrated really well and I thought he was solid.
"Toure is a very experienced professional. He's been around for a long time and he's a wonderful player. He's got great experience and he defends really well.
"Then in the second half, I thought the two boys did really well. Alberto fits into the mould of what we're looking to do here.
"We want technically-gifted players who work hard and some of his touches were fantastic. He's incisive with his passing and so I'm very pleased with him."