When it comes to defense, it all begins in the trenches. It sets the tone on each and every play.

The Kansas City Chiefs currently have nine defensive linemen on the roster as Organized Team Activities (OTAs) begin this week, including returning starters Chris Jones and Allen Bailey.

Jones, who is working his way back from a knee injury that he suffered in the playoffs, is looking to build on yet another strong season as he enters his third professional campaign. According to the folks at Pro Football Focus, Jones ranked as the fourth-best 3-4 defensive end in the NFL last season, excelling at both getting after the passer and stopping the run.

His play earned him a spot on PFF’s Top 25 Under 25 List earlier this week at No. 14.

Bailey, the veteran of the group, is also back after tallying two sacks and six tackles-for-loss in 2017. He's joined by Jarvis Jenkins and Justin Hamilton among returning players from last year.

Speaking of returns, Kansas City native Xavier Williams signed with his childhood team this offseason after spending the last three years with the Arizona Cardinals. A nose tackle by trade, Williams ranked as the 20th best defensive tackle against the run last season according to PFF.

The Chiefs added another run-stopper in the draft with the selection of Florida State product Derrick Nnadi in the third round (No. 75 overall). A member of the Bednarik, Outland and Nagurski award watch lists prior to his senior campaign, Nnadi ranked as the eighth-best interior defender against the run among 2018 prospects according to PFF.

Here's a look at all of the defensive linemen set to compete for the Chiefs during OTAs this year: