Complex sentence: During his first season with the Cantabrians, he was mainly restricted to cup matches, which also befell in the following; his La Liga debut came on 22 December 2007, as Racing crashed out at Sevilla FC (1--4).
Split into simpler sentences: During his first season with the Cantabrians, he was mainly restricted to cup matches. It was the same situation the following season He made his La Liga debut on 22 December 2007, as Racing fell to Sevilla FC (1--4).