Geren might be tight with GM Billy Beane, but that doesn’t mean he will be manager for life. Beane declined to extend Geren’s contract beyond 2011 during the offseason, focusing instead on giving the manager a more competitive club. The Beane-inspired movie “Moneyball” will be released this summer. Roll the credits on Geren if he fails to keep the A’s in contention.

Never mind that the White Sox exercised Ozzie’s option for 2012 in January, and that all was peaceful between Guillen and GM Ken Williams in spring training. For Ozzie, the hot seat is practically an endowed chair. Chicago’s season will truly kick off only after Ozzie and Kenny start going all Charlie Sheen on each other again.

First, owner Jeffrey Loria “awarded” Rodriguez only a one-year deal after failing to reach terms with Bobby Valentine and discussing a deal for Ozzie Guillen. Then, Loria criticized the Marlins’ play as “inconsistent and not acceptable” when the team started 5-13 . . . in spring training! With the Fish, irrational expectations and messy endings are the norm.

It’s the last year of his contract, and for five straight seasons the Tigers have produced a worse record in the second half than the first. Leyland is not solely to blame for those fades, but in January he acknowledged “my tail’s on the line.” Look for him to grow cranky if first baseman Miguel Cabrera comes under additional scrutiny for his DUI arrest.

He is about 10th in line to get blamed, behind the Wilpons, Bernie Madoff, Oliver Perez, Luis Castillo and whichever other goats the Mets produce this season. Still, Collins was combustible in his previous jobs with the Astros and Angels, and he is about to learn that a five-game losing streak in New York is like none other.

Expectations are rising, even with right-hander Stephen Strasburg out for the season and top draft pick Bryce Harper at least a year away from the majors. Scouts praised the Nationals’ improved fundamental play in spring training, but the team needs to carry it into the season with Riggleman entering the final year of his contract.

An in-season firing of La Russa is unimaginable, so he is not technically on the hot seat. Still, this easily could be La Russa’s last year in St. Louis. His contract includes a mutual option for 2012 — and La Russa likely will think twice about exercising his end if Albert Pujols bolts as a free agent.

The Cubs went a feel-good 24-13 after Quade replaced Lou Piniella last season. However, the plot thickened after the team gave Quade a two-year contract rather than hire popular Cubs Hall of Famer Ryne Sandberg. Quade, a baseball lifer who paid his dues, might be the next Leyland. But the Cubs have a way of screwing up a good thing.

New GM Kevin Towers elevated Gibson from interim to permanent manager, but gave him only a two-year contract. The intense, determined Gibson could prove too much for his players, prompting Towers to hire a replacement he is more familiar with. However, the manager figures to be the least of the Diamondbacks’ problems.

Nothing will happen to Mattingly this season; the Dodgers gave him a three-year contract and owner Frank McCourt likely will be held responsible for any of the team’s shortcomings. Problem is, Mattingly has no track record as a manager and no history with the Dodgers other than the three seasons he served as Joe Torre’s hitting coach. Donnie Baseball is effectively managing without a safety net.

Twelve of the 30 managers are entering their first full season, but even some of the newcomers will face immediate pressure. Once the season starts, reality will set in. Some manager will get fired. Probably multiple managers will get fired. Welcome to life on the hot seat. — Ken Rosenthal