wide receiver tweeted Thursday that he'll "be done playing football" if the NFL forces players to stand for the national anthem.
Matthews, a seventh-round pick in 2012 by the Miami Dolphins, later deleted the tweet.
The 28-year-old's comments follow a report Tuesday that the NFL and team owners will consider making it mandatory to stand for "The Star-Spangled Banner." The leagueWednesday that it hasn't made any changes to the anthem policy.
Even Cowboys owner Jerry Jones told player he would reprimand them if they kneeled for the anthem. Those comments prompted a meeting with Jones, coaches and player.
President Donald Trump has heavily criticized the NFL since he called for the league to "fire" any player who protests during the anthem at a Sept. 22 rally.