By Larry Fine
(Reuters) - Six teams head into Week 17 of the National Football League with a last chance to reach the Super Bowl tournament, while half a dozen head coaches may be facing their last game with axes poised to fall on Black Monday.
Last year, five NFL head coaches were fired on the Monday following the league's regular season finale and there is no shortage of candidates for similar treatment this season.
From Jim Harbaugh of the San Francisco 49ers (7-8) to Rex Ryan of the New York Jets (3-12) to Tony Sparano of the Oakland Raiders (3-12), coaching changes are expected.
Others in jeopardy of finding themselves on the unemployment line include Marc Trestman of the Chicago Bears (5-10) and Mike Smith of the Atlanta Falcons (6-9), with Washington's Jay Gruden (4-11), Tom Coughlin of the Giants (6-9) and Gus Bradley of the Jacksonville Jaguars (3-12).
Reasons for a possible change at the top vary.
For Harbaugh, who steered the 49ers to two NFC title games and a Super Bowl appearance in the three previous seasons, a growing rift with general manager Trent Baalke and the team's dreary performance this season point to a change.
The failure to develop a productive quarterback for the Jets could cost defensive-minded Ryan.
Quarterbacking troubles have also dogged Gruden and Trestman.
Gruden has been harshly critical of former number one pick Robert Griffin III and benched the 2012 Pro Bowler and Offensive Rookie of the Year, while Trestman has failed to get consistent results from strong-armed signal caller Jay Cutler.
Swapping out the coach is no guarantee of success.
Lovie Smith, the former Bears coach, has gone 2-13 in his first season with the Tampa Bay Buccaneers, a record matched by Ken Whisenhunt in his first campaign with the Tennessee Titans.
On the flip side, Jim Caldwell has trained the Detroit Lions to take a more disciplined approach and led them to an 11-4 record and a berth in the playoffs following a 7-9 mark last season under Jim Schwartz.
Replacements could come from the college ranks or from among highly regarded coordinators on NFL teams.
Among NFL coaches touted as top prospects to graduate to a head coaching job are defensive coordinators Todd Bowles of the Arizona Cardinals and Dan Quinn of the Seattle Seahawks, and offensive planner Adam Gase of the Denver Broncos.
(Reporting by Larry Fine in New York; Editing by Steve Keating.)