Aldon Smith's off-field issues have plagued him throughout his his short career. (USATSI)

The 49ers aren't counting on outside linebacker Aldon Smith to return this season, according to ESPN's Adam Schefter. Smith, the team's 2011 first-round pick, has 38 sacks in 35 career games but he has been plagued by off-field issues.

On Sept. 20, Smith was arrested on suspicion of DUI charges. Two days later, Smith took a voluntary leave of absence to undergo treatment at a rehab facility. Then, two and a half weeks after that, the Santa Clara County District Attorney's office filed three felony charges of possession of an assault weapon against Smith in conjunction with a June 2012 house party in which two people claimed they were shot.

Dan Skuta and Corey Lemonier have filled in during Smith's absence, and the 49ers have gone 2-0.