An examination of what the Jacksonville Jaguars must do after their loss to the San Diego Chargers:

The Jaguars' secondary has given up big plays on a pretty regular basis through the first four games, and that has to have Pittsburgh quarterback Ben Roethlisberger and receiver Antonio Brown excited about their trip to EverBank Field on Sunday.

The Jaguars have given up a league-worst 25 passing plays of 20 or more yards in four games, including six for touchdowns. The main reason has been coverage busts, particularly from the free safety position. That’s why the Jaguars benched Winston Guy before the Chargers game. Still, receiver Eddie Royal got open for two long TD passes, and watching the film showed both were coverage busts. One came because the Jaguars had linebacker Geno Hayes responsible for running with Royal and there was no safety help over the top. The other came because Guy, back on the field in a three-safety coverage, bit on an out-and-up move and got beat over the top.

The Jaguars cut Guy on Monday and are going with second-year player and sixth-round pick Josh Evans, who started against the Chargers and played well, according to coach Gus Bradley. Cornerback Dwayne Gratz is likely out this week with a concussion, so 2013 seventh-round pick Demetrius McCray will get the start.

That’s certainly not ideal in terms of personnel, but the Jaguars are limited by the lack of talented depth on the roster. But the bottom line is this: They have to do their job and be disciplined. If they are responsible for a certain player coverage area, that’s where they should be. It sounds simple, but it has been an issue all season in the secondary.

Coaches understand being beaten physically on a play. That happens. Mental mistakes, being out of position and freelancing have to stop happening. If not, Brown is going to add to his NFL-leading five touchdown catches.