The Texans had four defensive linemen hitting free agency this year. Joel Heath, Brandon Dunn, Angelo Blackson, and Christian Covington. The Texans extended a qualifying offer to Dunn, and resigned Blackson and Heath. Covington ended up being the odd man out. He signed a one-year contract to remain in Texas and play for the Dallas Cowboys.
Covington had one decent game as a pass rusher in 2018. Like the rest of the bunch, he's fine against the run, but can't muster a rush on his own. Throughout his rookie deal he showed signs of better play but torn biceps and never fully putting it together made these games and plays outliers not norms.
It will be interesting to see if that warlock Rod Marinelli can get Covington to provide constant distruption and evolve him to the next level as he's done to so many other defensive linemen before.