Per Aaron Wilson of the Houston Chronicle, Clowney's decision to skip the Pro Bowl is due to elbow and wrist injuries.
Clowney had a breakout season for the Texans in 2016. After two disappointing years to start his career, the No. 1 overall pick in 2014 set career highs in games played (14) and sacks (6.0) in helping Houston's defense overcome the loss of J.J. Watt.
Sam Monson of Pro Football Focus noted after Houston's playoff win over the Oakland Raiders that Clowney was performing at a different level than previously seen:
(Clowney) is pretty close to realizing his potential just at the right time for the Houston Texans. He was the best player on the field in the Wild Card game against Oakland (a field that included Khalil Mack), and since Week 10 of the season he has been one of the game’s most dominant edge defenders.
Even though the Texans would lose to the New England Patriots in the AFC Divisional Round, Clowney again showed off his skills by hitting Tom Brady twice and recording one tackle for loss.
Given how important Clowney became to Houston's defense in 2016, risking further injury in an exhibition isn't worth it.
Dunlap, who was a Pro Bowler in 2015, had another strong season for the Bengals with eight sacks and 15 passes defensed. He wasn't the dominant force off the edge he was last season with 13.5 sacks, but his ability to knock down passes at the line of scrimmage made up for it.
The AFC and NFC will lock horns at the Pro Bowl on Jan. 29, one week before this year's Super Bowl.