Reserves giving 49ers defense a boost; more of same needed against Texans

New blood is helping the San Francisco 49ers' defense play some of its best football of the young season.

The 49ers got some standout efforts from reserves asked to take expanded roles during last week's 35-11 rout of the St. Louis Rams, a performance that vaulted San Francisco to No. 4 in the NFL's defensive rankings.

With All-Pro middle linebacker Patrick Willis still questionable to return this week, and All-Pro outside linebacker Aldon Smith still out indefinitely, the 49ers will be asking their supporting cast to step up again Sunday when they host the Houston Texans and the league's fifth-ranked offense.