Gerrard began to regularly partner Redknapp in central midfield for the 1999–2000 season. After starting the derby against Everton on the bench, he replaced Robbie Fowler in the second half but received his first career red card for a challenge to the upper leg of Everton's Kevin Campbell shortly afterwards in a game Liverpool lost 1–0. Later that season, Gerrard scored his first senior goal in a 4–1 victory over Sheffield Wednesday. However, he began to suffer from persistent back problems, which sports consultant Hans-Wilhelm Müller-Wohlfahrt later diagnosed as a result of accelerated growth, coupled with excessive playing, during his teenage years. He was then beset by groin injuries that required four separate operations.