ESPN's Adam Schefter, among others, is reporting Steelers safety Ryan Mundy was fined $21,000 for a helmet-to-helmet hit on Raiders wide receiver Darrius Heyward-Bey in Oakland's 34-31 win over Pittsburgh in Week 3.

Heyward-Bey fell immediately to the ground and appeared unconscious. He was on the ground for several minutes, and was taken to an area hospital from the field.

He remained overnight in the hospital, but was released Monday and the team said he's expected to make a full recovery from the concussion and neck strain he suffered in the incident.

It's the first fine for Mundy, and the second the Steelers have incurred in 2012. Linebacker Lawrence Timmons incurred a $21,000 fine for a hit on Jets quarterback Mark Sanchez in the Steelers' 27-10 win in Week 2.

Like Timmons', Mundy's fine was expected, and appeared to be justified based on league rules.

The Steelers have a bye in Week 4, and will host the Philadelphia Eagles in Week 5.