CLEVELAND — Brodney Pool’s fifth season with the Cleveland Browns was ended prematurely by a concussion. It doesn’t appear he’ll get a sixth one.

The safety, whose NFL career has been threatened by a series of head injuries, was not given a second-round tender by the club on Thursday, making him an unrestricted free agent.

The Browns did give second-round tenders, a guaranteed $1.75 million salary for next season, to running back Jerome Harrison, linebackers D’Qwell Jackson, Matt Roth and Jason Trusnik, safety Abram Elam and fullback Lawrence Vickers. Those players can sign offer sheets with other teams, but the Browns would have seven days to match the offer or they’ll receive a second-round draft pick as compensation.

Pool, a second-round pick in 2005, missed Cleveland’s final five games in 2009 after sustaining at least his fourth known concussion. The easygoing 25-year-old made 10 starts before getting hurt.

While the Browns prepared for the opening of free agency, Pro Bowl return specialist Josh Cribbs, who has been trying to get the club to give him a new contract, announced he will be having a press conference on Friday.

Cribbs plans to address the media before an appearance at the Cleveland Auto Show. A statement sent out by his marketing representative said Cribbs would “make a major announcement.”

“It’s not very often that fans get to hear an announcement from a player in person,” Cribbs said in the statement. “And, it’s even more unlikely that they’re given a chance to speak to that player right after that announcement has been made.”

A Browns spokesman said the team is not involved with Cribbs’ announcement.

Cribbs’ agent, J.R. Rickert, said in an e-mail response that he does know what Cribbs plans to announce.

Since the end of the 2008 season, Cribbs has been asking the Browns to restructure the six-year, $6.7 million contract he signed in 2006. Cribbs, who holds the NFL record with eight kickoff returns for touchdowns, wants more guaranteed money and has often referred to the four-year, $40 million extension Devin Hester got from the Chicago Bears.

Cribbs has threatened to hold out in the past but continued to play. He has become Cleveland’s most popular player with many fans siding with him in his bid to get more money.

When last season ended, Cribbs and his representatives were irate over a proposal made by the club’s previous management regime. At one point, Cribbs said it was “unlikely” that he would play another game for the Browns.

However, new president Mike Holmgren expressed his intent to keep Cribbs and the sides have had productive talks in recent weeks.