On Friday afternoon, minutes before Virginia Tech Coach Frank Beamer introduced three new assistant coaches during a news conference, Hokies cornerback Antone Exum stood in the back of the room discussing his basketball talents with running backs coach Shane Beamer.

Exum joked that, in light of Erick Green’s 35-performance against Virginia the night before, he had played with Green on campus and could hold his own. But it appears pickup basketball has thrown a wrench in what looked like a promising senior year on the gridiron.

Exum has torn his right ACL and lateral meniscus, Virginia Tech announced Sunday evening, and could miss the start of the 2013 season as a result. Two people in the football program with knowledge of the situation confirmed that Exum suffered the knee injury while playing pickup basketball on campus on Saturday.

The Glen Allen native is expected to be out for the next 6-9 months, which means Exum could be return as late as the end of October. The Hokies face two-time defending national champion Alabama in Atlanta to open the regular season.

Exum’s injury is a significant blow for a defense that improved steadily after a slow start to last season and brings back most of the key contributors from that unit. Exum, who switched from safety to cornerback last spring, showed the most progress once he got adjusted to his new position.

A second team all-ACC selection, Exum finished with a league-high 16 pass breakups and a team-high five interceptions. He was named the Russell Athletic Bowl’s most valuable player when the Hokies kept Rutgers’ offense out of the end zone en route to a 13-10 victory.

Without Exum, some of Virginia Tech’s unheralded defensive backs will be given a chance to step into a starting role alongside rising senior Kyle Fuller during spring practice. Freshmen Donaldven Manning, Donovan Riley and Davion Tookes could all factor in at the position. The Hokies also expect five defensive backs, including Good Counsel All-Met Kendall Fuller, to sign national letters of intent as part of their 2013 recruiting class.

Exum, though, was considered one of the faces for next year’s defense after deciding not to declare for the NFL draft earlier this month. To close Friday’s news conference, he even took the microphone and asked new Virginia Tech wide receivers coach Aaron Moorehead if he was ready to take on the Hokies secondary every day in practice.

Suddenly, though, the question is when Exum will be ready to back up that talk on the field.