Complex sentence: By the 1977 season, John Stearns had taken over as the Mets' starting catcher and, in August, after twelve seasons with the Mets, Grote was traded to the Los Angeles Dodgers for two players to be named later.
Split into simpler sentences: By the 1977 season, John Stearns had taken over as the Mets' starting catcher. In August, during his twelfth seasons with the Mets, Grote was traded to the Los Angeles Dodgers for two players to be named later.