Rodri entered the fray in the second-half for his first appearance since early November.
“He changed the game. He proved in 45 minutes that he is the best in his position,” said Guardiola.
“Football is about the players, in the buildup we struggled and with Rodri we struggled less.
“He broke the lines, we moved better and hopefully one year and a half without him we missed him a lot and hopefully he can stay because he makes us a better team.”
On the game, Guardiola also said: A really good game, especially the second half.
“The first half was tight, we just missed to score a goal in the six-yard box.
“We had many there, good actions against a fantastic team but I’m so proud and delighted at the way we played in a difficult stadium against difficult opponent.
“We did everything to win but we could not win it.”