Chicago Bears rookie linebacker Jon Bostic received a $21,000 fine from the NFL for what the league interpreted to be a hit on a defenseless receiver in a preseason game, NFL.com reported on Wednesday.

Bostic forced an incompletion with a jarring blow on San Diego wide receiver Mike Willie during the third quarter of last Thursday's contest against the Chargers. Though no penalty was called on the play, the league determined that helmet-to-helmet contact occurred and should have warranted a flag.

Teammate and fellow linebacker Lance Briggs tweeted his displeasure at the league when informed of Bostic's fine.

"Shaking my head moment. Nfl fines jon bostic 21k for his clean hit against the chargers," wrote Briggs.

Bostic, who played collegiately at Florida, was selected by the Bears in the second round (No. 50 overall) in April's draft.