The penalties stemmed from extracurricular activity involving Jennings and Cardinals defenders. The first incident involved Jennings and Cardinals cornerback Starling Thomas, resulting in offsetting penalties, while the second occurred when the 49ers receiver got physical with cornerback Sean Murphy-Bunting.
Both Jennings and Murphy-Bunting were ejected with 6:26 remaining in the first half.
Jennings wrapped up the game with seven catches for 52 yards on 10 targets, finishing the season with 975 receiving yards—just shy of the coveted 1,000-yard milestone.
Over the weekend, the NFL fined Jennings $11,817 for an altercation against the Detroit Lions last week.
Jennings' absence against the Cardinals adds to the 49ers' challenges, as the team was already without wide receiver Deebo Samuel, who is inactive due to rib and wrist injuries.