Contract length isn’t necessarily a guarantee of job security.  Over the years, we’ve seen countless examples of teams who have made surprising management changes in the wake of an unexpected losing season (such as the Braves firing ex-general manager Frank Wren) or simply due to new candidates coming onto the market (such as the Cubs firing Rick Renteria when Joe Maddon became available).  Similarly, some managers and GMs aren’t troubled by being a so-called “lame duck” entering their last year under contract.  Some have unofficial handshake deals to continue on in their roles as long as they wish, or some actually prefer a one-year deal  — i.e. former Tigers skipper Jim Leyland — if they aren’t sure how much longer they want to remain in baseball.

For other executives and bench bosses, however, an expiring contract can indicate that they’re under significant pressure to get results in their last year under contract.  Here’s a list of managers and GMs who are believed to be entering the last year of their contracts in 2015.  (I say “believed to be” since some clubs keep front office contract terms private, so there could be a few more GMs who are also entering their last guaranteed season, or perhaps some of the names on this list have already been quietly signed to extensions.)  As always, a big tip of the cap to Cot’s Baseball Contracts for many of these details.

• Blue Jays: John Gibbons’ rolling contract will guarantee his 2015 team option on New Year’s Day, and also add another club option to his deal that covers the 2016 season.  The relationship between Gibbons and GM Alex Anthopoulos is known to be a firm one, though with the Jays so clearly set on contending in 2015, a disappointing record could lead to some questions about Gibbons’ future with the team.
• Braves: Atlanta’s late-season collapse cost Wren his job, though manager Fredi Gonzalez retained his spot in the team’s dugout.  This is an interesting situation to monitor given how the Braves’ trades of Justin Upton and Jason Heyward indicate that they’re at least partially rebuilding, though the additions of Shelby Miller and Nick Markakis hint that they intend to stay competitive.  All indications are that the Braves plan to contend when they move into their new ballpark in 2017, so if the team will look to somewhat tread water until then, Gonzalez could be safe.
• Brewers: Doug Melvin has been Milwaukee’s general manager since September 2002, taking over a struggling franchise and helming them to two postseason appearances (in 2008 and 2011) during his tenure.  Since that most recent playoff berth, the Brewers have posted two winning seasons sandwiched around a poor 2013 season for an overall 239-247 record.  The club’s payroll cracked the $100MM threshold last year and projects to do the same in 2015, so the Crew will be expected to rebound from last season’s second-half struggles.  Another middling record won’t cut it in the increasingly-competitive NL Central, so it’s possible Melvin could be on the hot seat if the Brewers aren’t in contention.  That said, given Melvin’s history with the team, I’d guess he’ll receive a two- or three-year extension to give him a bit more time to get things on track.
• Mets: Terry Collins’ role in his first four seasons as the Mets’ manager has been to act as a teacher and mentor to the club’s young players as the Amazins have been rebuilding.  All signs point to 2015, however, as the season when the Mets are looking to again become a factor in the playoff race.  If the Mets get off to a slow start, it wouldn’t be a surprise to see Collins fired in favor of a manager who can theoretically help the team take that next step.
• Nationals: Matt Williams is technically entering his walk year, though the Nats hold team options on the manager’s services for 2016 and 2017.  Barring a total collapse in Washington next year, Williams isn’t going anywhere.
• Padres: Bud Black is the rare manager who has lasted in his position through both an ownership change and four different general managers.  Though Black has only posted two winning records in his eight seasons as San Diego’s manager, he is still regarded by many as one of the game’s better skippers, and it’s indeed hard to fault Black given the Padres’ front office instability and sub-par rosters during his tenure.  2015 will be a different story, as new GM A.J. Preller has made several major acquisitions to help revamp the Padres’ lineup.  Black has said he’s not worried about not having an extension in place, and while he probably has reason to feel secure given how long he’s lasted in San Diego already, another losing season could convince the new-look Padres to make a change on the bench.
• Phillies: The Jimmy Rollins trade indicates that the Phillies are finally embarking on a much-needed rebuild, and it appears that GM Ruben Amaro Jr. will be the one to oversee it as he enters the last year of his contract.  You’d think the Phils would’ve already made a change if they wanted a new face to usher in this new era for the team, though it’s worth noting that the Phillies’ upper management situation is also in flux as general owner David Montgomery is on leave while undergoing cancer treatments.  (Former GM Pat Gillick is filling in for Montgomery in the interim.)  It could be that Amaro’s future in Philadelphia won’t be addressed until his contract is actually up, or when Montgomery has recovered enough to resume his duties.
• Royals: Ned Yost could hardly have made a better argument for a new deal by leading Kansas City to within a game of a World Series title.  Royals GM Dayton Moore hinted that Yost’s contract would be addressed later in the offseason, so it’s probably just a matter of time before Yost is extended beyond 2015.
• Tigers: Dave Dombrowski is entering the last year of his contract as Detroit’s general manager, president and CEO.  Given his track record with the Tigers, it’s safe to assume that Dombrowski is one of those “has the job for as long as he wants” executives and he’ll get an extension sooner rather than later.

The original version of this post incorrectly indicated that Marlins president of baseball operations Michael Hill and GM Dan Jennings were heading into the final years of their contracts. In fact, both are already under contract through 2018. Hat tip to MLB.com’s Joe Frisaro.