INDIANAPOLIS — Hurry back, All-Pro linebacker Darius Leonard. Your defensive teammates need you, badly.

The Colts put on an atrocious defensive performance in their 31-24 loss to the Oakland Raiders on Sunday.

The Colts were supposed to take a step forward defensively this season after surprising many by finishing 11th overall last season and using seven of 10 draft picks on that side of the ball back in the spring. But the unit hasn’t shown signs of the required improvement so far this season. Sunday was another example of that.

The Colts could have definitely benefited from using Leonard (concussion) and safety Malik Hooker (knee), their two best defensive players, but that doesn’t explain the defensive line’s getting bullied by Oakland’s offensive line and an inability to generate a pass rush.

Oakland quarterback Derek Carr opened the game by completing 11 of his first 13 pass attempts with two touchdowns. Carr was able to stand back in the pocket to go 21-of-31 for 189 yards because the Colts sacked him only once.

The Colts appeared to be on their way to having a good pass rush when they recorded eight sacks in the first two weeks of the season. But that pass rush has vanished the past two weeks, as they had only one sack in those two games. The Raiders also rushed for 188 yards.

Things won’t get any easier for the Colts next week because they have to face Kansas City and reigning NFL MVP Patrick Mahomes on the road in Week 5.

Pivotal play: There would be no Andrew Luck-type comeback by Colts quarterback Jacoby Brissett. Not even close, in fact. The Colts got the ball back at their own 25-yard line with 2 minutes, 28 seconds remaining. Brissett wasn’t able to get the Colts into Oakland territory because he locked in receiver Zach Pascal and Raiders safety Erik Harris had an easy interception that he returned for a touchdown to seal the victory on the second play of the drive. Brissett went from having the most efficient game of his career against Atlanta in Week 3 with 310 yards, including completing his first 16 passes, to going just 24-of-46 for 265 yards with three touchdowns while trying to spread the ball around without T.Y. Hilton and Devin Funchess in the lineup. Pascal (72 yards) was the only player to have more than 48 yards receiving for the Colts.

Troubling trend: It was like early in the 2018 season all over again for the Colts and their inability to catch the ball. They were without their top two receivers in Hilton (quadriceps) and Funchess (clavicle), but that shouldn’t have stopped the rest of the skill-position players from catching passes from Brissett. The Colts had five drops, all in the first half. Tight end Eric Ebron had three of the drops, including two that would have given the Colts a first down. Things were so bad for him that he threw his helmet on the sideline twice in one sequence. There’s no guarantee that help is on the way for the Colts, either, as Hilton had been listed as doubtful for Sunday’s game and Funchess is on injured reserve.