The Oakland Raiders thought they would be going into the season with Antonio Brown leading their receiving corps. Instead, Brown didn't even play a single preseason game before eventually requesting his release after a series of events.

As one would expect, Raiders head coach Jon Gruden says that the team's offensive gameplan changed after Brown's departure.

“It's caused us a little bit of … rethinking,” Gruden said, according to Paul Gutierrez of ESPN.com. “When you lose your starting ‘Z,' who arguably is a great player, I don't think anyone's going to dispute that you have to replace him. And we're making an effort to move Tyrell [Williams] around; we're bringing on some younger guys. J.J. Nelson also got hurt; don't forget that. He was hurt. Dwayne Harris got hurt, so we've had some multiple things to deal with, and we're dealing with them.”

The Raiders got off to a good start this season, defeating the Denver Broncos by a score of 24-16 in Week 1. But since then, it has not exactly been smooth sailing for Gruden's club.

Oakland followed up its win over the Broncos by getting hammered by the Kansas City Chiefs, and this past weekend, the Raiders were routed by the Minnesota Vikings.

Oakland has mustered just 24 points over the last two weeks, and its offense ranks 25th in the NFL overall.

That shouldn't come as much of a surprise, as the Raiders' weapons are very thin without Brown, as Tyrell Williams, historically a No. 2 wide out, has been elevated to the role of Derek Carr's top option in the aerial attack.

Oakland will take on the Indianapolis Colts on Sunday.