With the season now more than a month old, it's about time for rumors to start emerging about this and that manager's job security. On Tuesday, CBS Sports HQ MLB insider Jim Bowden offered up some conjecture on that front, noting that he would not be surprised if New York Mets skipper Mickey Callaway ends up being the first manager fired this year (watch the video above).

While Bowden wasn't offering inside information, his quip got us to thinking: what other managers might be on the hot seat? We put our heads together and came up with four skippers who should be feeling uneasy. They're presented below in alphabetical order.

Do note that we're not claiming these managers are on the hot seat -- merely that they would appear to be nearing that point for the reasons provided.

1. Mickey Callaway, New York Mets

Callaway is in an unenviable predicament. He's a second-year manager working under a first-year GM who was previously a player agent. There's no telling what Brodie Van Wagenen wants from a skipper. Van Wagenen did spend the winter upgrading the Mets' analytics department and roster, however, and made an interesting decision by naming Jim Riggleman bench coach. Riggleman has become the coaching equivalent of a pinch-hitting specialist, having served as an interim manager with the Seattle Mariners, Washington Nationals and most recently last year with the Cincinnati Reds. Will Riggleman add another team to his collection? It depends on how effectively Callaway can guide the Mets to a winning record.

2. Davey Martinez, Washington Nationals

On the one hand, few teams have disappointed more the past 13 months than the Nationals, who just fired a coach and are currently ensconced in a potential season-defining 20-game stretch. Martinez is at least partially to blame, and has been a clear downgrade from predecessor Dusty Baker. On the other hand, the Lerners -- never ones for spending much money on the managerial position -- don't seem inclined to have to pay two skippers for two seasons. Were Martinez to get canned, GM Mike Rizzo would be hiring his sixth manager. That's unheard of these days.

3. Don Mattingly, Miami Marlins

Mattingly would almost certainly be gone had he not signed a four-year deal to manage under the Marlins' previous ownership group. You have to imagine Derek Jeter and crew are going to make a change ahead of next season, installing someone of their own choosing. Given how poorly the Marlins have played out of the gate -- and as of Sunday they were on pace to do something previously undone since the 1800s -- it stands to reason Jeter and company could make Mattingly the fall person over the coming weeks, well before his contract expires.

4. Ned Yost, Kansas City Royals

As with Mattingly, Yost's deal is up at season's end. The difference is Yost has been rumored to be nearing retirement for years now. Whether he decides to hang up his hook after the year is anyone's guess. The Royals, for their part, have suggested they'd be open to having him continue to manage for as long as he wants. At some point we suspect they'll decide they'll want more of a long-term fixture. As such, we're including Yost, albeit with the acknowledgement that he seems less likely to be canned this season than the three others above.