The Turkey international has struggled for game time this season but was drafted in after Jonny Evans was ruled out with a hip injury.
Harry Maguire was also given time off following the birth of his daughter in the week and Rodgers said he was delighted with his first look at Soyuncu.
"A special mention today to Cags, our centre half," said Rodgers.
“He was only told this morning he was playing and that is testament to him.
“I thought his performance, apart from a loose pass at the end when he was tired, was outstanding having not played for five months.
“He was very good and it was a very good team performance and to score four goals in the Premier League is never easy. They played very well and deserved the win."