The writing is on the wall: major changes are coming in the San Francisco 49ers' organization.

Head coach Jim Harbaugh is likely gone. If the team doesn't promote from within (Eric Mangini and Jim Tomsula have been mentioned as potential Harbaugh replacements), then it is likely that most of the staff could be gone as well. Such turnover in coaching positions would have a ripple effect on the roster as well.

Matt Barrows of the Sacramento Bee weighed in on the futures of several 49ers mainstays.

"I think that if [defensive coordinator Vic] Fangio or [defensive line coach] Tomsula returns in some capacity it increases the chances that [Justin Smith] returns," Barrows wrote.

Smith will count $6.4 million against the cap in 2015, but has no guaranteed money remaining on his contract besides roster bonuses.

But what about some other high profile players such as Patrick Willis, Frank Gore and Michael Crabtree?

Barrows listed the chances of them returning as follows:

"Willis: 90 percent

Smith: 50 percent

Gore: 42 percent

Crabtree: 20 percent."

There's a reason Crabtree, a former first-round pick, is the least likely to return. His play hasn't warranted a new contract with San Fran.

"This season was not the best time for Michael Crabtree to lay an egg -- in a contract year -- but that's exactly what the 2009 first-rounder has done," ESPN's Neil Hornsby wrote.

"In truth, he's had only one good season out of six for San Francisco. Crabtree's PFF grades, in order from 2009, read minus-1.6, minus-4.6, minus-1.9, plus-21.2, plus-0.9 (on only 372 snaps because of injury) and now minus-7.9. That huge spike in 2012 stands in stark contrast to the mediocrity surrounding it, and serves to demonstrate the huge talent he can bring to bear -- on occasion."

"In 2012, the Niners could simply throw Crabtreee the ball short of the yard marker on third down and watch him either ride the tackle or break it to move the chains. He was an awesome weapon. But this year, he has dropped more balls (10) than he has broken tackles (nine), and it has left the front office a difficult choice. They can either let Crabtree go and potentially watch him return to his 2012 form with another team, or hope 2012 wasn't the exception to the rule. One in six is not enough for me, and if I were advising the 49ers, with interesting receiver options in both the draft and free agency, I'd pass."