Bielsa says Rodrigo was always playing catch up due to joining Leeds late in the summer transfer window from Valencia.
He explained, "To explain exactly, Rodrigo arrived at the start of the competition with no pre-season for us. It took him four weeks to become a starter and after playing his best game, which was against Aston Villa, then he became sick. He was ill for 20 days, then after that to get back to his best state took him a month.
"He played 10-12 games at a medium to high level then picked up that injury which he was out for five weeks with. And perhaps this segment where he didn't play for 40 days was too quick because he's a player that gets his best physical state by gradually increasing the minutes. He played 45 mins with the U23s. 45 mins against West Ham and against Chelsea who is one of the teams who has the biggest rhythm in the league alongside City. I had to bring him back earlier because my estimate is that he shouldn't have played more than 50 minutes.
"He becomes a starter when he's in a good state of form. When he has been without playing for over a month his return is not instant. We have seen what he is a capable of. He is a great striker when he finds his best form."