Perry Riley is one of the best linebackers left with just over a month until the NFL season kicks off. Worst for him, there aren't really any rumors that he'll be finding a job soon. Training camp and the preseason will provide an opportunity for Riley, though, as teams begin to deal with injuries and depth concerns at the linebacker spot. When that happens, these four teams may come calling for the veteran linebacker.

4. Cleveland Browns

The Browns are slowly starting to build something. They have more talent on their roster than any time in the past decade, including at the outside linebacker spot with Jamie Collins.

That talent has not quite made it to the inside linebacker position yet, though, where the team is planning on starting Dominique Alexander and Christian Kirksey. Those names aren't familiar to the average NFL fan... or even the dedicated NFL fan. Riley would definitely be an upgrade in the middle.

3. Los Angeles Chargers

The team is hitting the reset button as they move from San Diego to the Los Angeles suburbs. Their offense, while aging in some regards, is ready for that move. The defense is not. The starters at inside linebacker are Jatavis Brown and Denzel Perryman. Both young players have looked decent at the beginnings of their careers, but a veteran presence would be of great use to the team.

Either Riley or Zach Orr could be that presence if the Chargers dip into free agency.

2. Detroit Lions

Jarrad Davis has plenty of potential. But the first-round pick is a rookie and one who was not always expected to be drafted as high as he was. He could use somebody to learn behind and Perry Riley could be that somebody. He has over 500 career tackles and can play a versatile role.

The Lions have playoff aspirations this season, but they may need to look towards free agency to help reach those goals.

1. Oakland Raiders

The return? Riley was popular after the Raiders desperately added him to their ranks in 2016, suggesting that a 2017 comeback would be a shoo-in. It hasn't happened, but the need is still there.

He recorded 48 tackles and two forced fumbles in just 11 games last season. Zach Orr may be a better choice at middle linebacker, but Riley is already familiar with the team, the fans, and the defensive schemes. He isn't a long term solution for the team. But he would be a solid addition for a team that wants to bring a championship to the Bay Area before departing for Las Vegas.