Juventus began the 1998–99 Serie A with a 2–1 defeat in the 1998 Supercoppa Italiana at the hands of Lazio, although Del Piero was able to score from a penalty. On 8 November 1998, Del Piero picked up a serious knee injury in the final minutes of a 2–2 draw with Udinese; this kept him out of action for the remainder of the season, as he managed only 2 goals. The club struggled without him, finishing the league season in a disappointing sixth place. Juventus did manage to reach the semi-finals of the 1998–99 UEFA Champions League, losing out to eventual champions Manchester United. Following his serious injury, Del Piero underwent a muscle strengthening regime in order to adapt to the increasingly more physical and athletic demands of twenty-first century football, which allowed him to compensate for the loss of some of his pace and agility. Due to his dramatic weight gain and physical development during this period, as well as the club's success during the mid to late 90s, Del Piero, along with several other Juventus players and staff members, was claimed of being involved in illegal performance-enhancing drug abuse; after a lengthy investigation, the club's staff members incriminated were eventually cleared of all doping allegations in 2005.