Read this article and answer this question The Panthers opened the regular season at home against the Atlanta Falcons on September 10. They lost, in what many fans and players alike referred to as an embarrassing game, 20-6. Kicker John Kasay was the only scorer for Carolina with two field goals. However, it is important to note that the team's biggest playmaker, wide receiver Steve Smith, did not play due to a hamstring injury. During the game, tackle Travelle Wharton seriously injured his left knee, effectively ending his season. He was later placed on injured reserve. Wharton had started the previous 28 regular season games for Carolina at either left guard or tackle. Carolina also lost its starting center, Justin Hartwig, and middle linebacker Dan Morgan for the season.  With the loss, the Panthers started out their season 0-1.
How many players did the Panthers lose to injury during the game?
3