The Sports Xchange

Tennessee Titans quarterback Marcus Mariota missed practiceThursday for the second consecutive day due to a knee injury and could be in jeopardy of missing Sunday’s game against the Atlanta Falcons.

Backup quarterback Zach Metterberger is being prepared to start in case Mariota can’t play.

Mariota suffered a sprained MCL in his left knee during last Sunday’s game against the Miami Dolphins.

Tennessee coach Ken Whisenhunt was non-committal on whether or not he would start Mariota, and said he doesn’t have a firm rule about whether a player who didn’t practice all week can start a game.

–The Chicago Bears signed defensive lineman Ziggy Hood and terminated the contract of vested veteran defensive lineman Jeremiah Ratliff.

Ratliff is a four-time Pro Bowl selection who started 102 games for the Dallas Cowboys and the Bears since 2005. His career totals include 380 1/2 tackles, 35 sacks, 27 1/2 tackles for loss, 18 pass breakups, 13 fumble recoveries and five forced fumbles.

In three seasons with the Bears, Ratliff started 17 games, including two this year, and totaled 63 1/2 tackles, eight sacks, 2 1/2 tackles for loss and 18 quarterback pressures.

Ratliff was suspended for the first three weeks of this season because of an DUI case in Texas. He reportedly had a heated argument with Bears general manager Ryan Pace on Wednesday and was escorted out of the team’s training facility by security.

–Buffalo Bills wide receiver Percy Harvin is not with the team in London but has been the most discussed player on the team this week.

Harvin did not travel with the team for Sunday’s contest against Jacksonville because of what coach Rex Ryan described as a personal issue. He still wasn’t around Thursday, when the Buffalo News reported Harvin might contemplate retirement because he’s frustrated by hip and knee injuries.

ESPN reported hours later, citing a source, that Harvin’s frustration over injuries was accurate but refuted reports he is weighing retirement.

–Dallas Cowboys wide receiver Dez Bryant has not practiced this week and the team charter is headed for New York on Friday ahead of the Week 7 game against the Giants.

According to coach Jason Garrett, the Cowboys aren’t ruling Bryant out, but he must practice in order to be considered among the team’s active players Week 7.

Bryant did not practice Wednesday or Thursday. He last played Week 1, when he left the Sept. 13 primetime win over the Giants in the third quarter with a broken foot.

–Minnesota Vikings defensive end Everson Griffen underwent precautionary heart-related tests, according to a report by ESPN.

Griffen missed last Sunday’s game against the Kansas City Chiefs when he became ill before kickoff. He was taken to a hospital and tests ruled out an irregular heartbeat.

Griffen met with reporters on Thursday and indicated that he plans to play against the Detroit Lions on Sunday.

–Wide Receiver Brandon Lloyd announced his retirement after playing 11 NFL season.

Lloyd, 34, caught 399 passes for 5,989 yards and 36 touchdowns while playing for six different teams.

Lloyd’s best season came in 2010 with the Denver Broncos when he had an NFL-best 1,448 receiving yards while also setting career highs with 77 receptions and 11 touchdowns.

–The New England Patriots released defensive lineman Khyri Thornton from the 53-man roster and offensive lineman Brennan Williams from the practice squad.