He had a 10.23 ERA and a 1.043 OPS allowed his final 5 starts with Texas. He allowed 7 ER in his final start, and then It took him 8 starts to give up 7 ER total with the Cubs. he literally said it himself and it was evident on video. you can go ahead and argue pennant race magic instead, though. nah, he just wasn't trying as hard in texas because he was bored in a potential free agent year.