Pettis did not practice Thursday due to an illness, Nick Wagoner of ESPN.com reports.
Pettis will have a week and a half to return to full health ahead of the Super Bowl on Feb. 2, so there's not yet any reason to consider his availability in jeopardy. More pressingly, the second-year wideout has not recorded a snap on offense since Week 12 of the regular season. Having tumbled down to a depth role in San Francisco's receiver corps, Pettis will be an unlikely candidate to factor into the team's plans on offense even if he's at full strength.