The 24-year old striker netted his third goal in three consecutive 1-0 wins for the Reds to kick off the season with a 100% record and Rodgers was happy to see him in fine form even after a slight injury.
"I am delighted with his application," said Rodgers.
"He was nowhere near fit.
"He played full game and extra time in the week (scoring two goals in the Capital One Cup win over Notts County) and he had a slight knock on his thigh.
"Even at 70 per cent he will be as good if not better than most Premier League strikers but you have to have that will and desire to put yourself out there.
"He can always be a threat."