The Memphis Grizzlies have been one of the biggest surprises in the NBA with an 18-11 record despite multiple injuries to key players. Among those stepping up to keep Memphis afloat in the Western Conference is guard Tony Allen, who is now drawing interest around the league.

According to Ronald Tillery of The Commercial Appeal, the Grizzlies are listening to offers from teams that have checked in regarding Allen's availability in a potential trade.

While it's unclear which teams are looking, Allen's main appeal lies in his defense. The three-time NBA All-Defensive First Team member is among the league leaders in steals per 48 minutes this season. Earlier this year, Kobe Bryant called Allen the best defender he ever faced.

Allen, a 13-year veteran making $5,505,618 this season, began his career with the Boston Celtics before joining Memphis in 2010.

The Grizzlies almost traded Allen to the Minnesota Timberwolves in 2014, per former CBSSports.com NBA insider Ken Berger.

Allen will turn 35 in January and is set to become an unrestricted free agent after the season.

-- Nick Ostiller