1983 started out terribly for Ruthven, starting out the season with a 1-3 record and a 5.61 earned run average for the Phillies. On May 22, the Phillies traded Ruthven to the Chicago Cubs, along with minor league pitcher Bill Johnson, for relief pitcher Willie Hernández. While the Phillies won the National League pennant that season, the Cubs would finish fifth with a 71-91 record, 19 games behind the Phillies. Ruthven pitched better for the Cubs, going 12-9 with a 4.10 earned run average. 1983 was the last season in which Ruthven won ten or more games.