The San Francisco 49ers need roster space with several players poised to return and are looking to create room before Tuesday's 4 p.m. ET trade deadline, according to sources.

Aldon Smith is among the key defensive players poised to return soon for the 49ers. Kelley L Cox/USA TODAY Sports

Come Tuesday's trade deadline, the 49ers will be interested in dealing a defensive player or two on the back end of their roster to get back a late-round pick and, more important, a roster spot or two, the sources said.

Linebacker Aldon Smith is poised to return to the roster as early as this week while defensive tackle Glenn Dorsey is eligible to come off the injured-reserve designated-to-return list in two weeks. Also, linebacker NaVorro Bowman is poised to return in late November and running back Marcus Lattimore potentially could return soon from from the non-football injury list.

The 49ers simply don't have space for the infusion of talent they'll be receiving in the next month and they need to somehow try to create it in the most productive way possible.

Tuesday's trade deadline could provide that opportunity.