Yesterday’s announcement that the San Francisco 49ers signed Anthony Davis to a five-year extension was one of those unexpected moves that actually wasn’t all that surprising. With free agency still meandering along, trades getting made here and there, and the NFL Draft to prepare for, not many people were sitting on pins and needles waiting to hear about the 23-year-old right tackle getting locked up. Still, the reaction to the news was a collective, “Yeah, that sounds about right. Just Baalke and Paraag doing doing what they do. That is, when they aren’t braagging to everyone about the extra a’s in their naames.”

/Rimshaat

Since these NFL execs clearly never sleep, they’re probably working on more extensions to make planning for future years slightly easier. So who else might sign a new deal in the not-too-distant future? Colin Kaepernick is out, for one. Due to the new CBA, Kaepernick and the 49ers can’t change anything relating to his contract terms until after the 2013 season. So you can rest assured that Baalraag* aren’t in talks with Kaepernick’s agents, because that would be breaking the rules and neither party would EVER do such a thing.

*Doesn’t quite have the same ring to it that Harbaalke does, so hopefully we can just agree to forget I ever tried that one out. Ahem.

Aldon Smith and Bruce Miller were drafted the same year as Kaepernick, so they’re in the same boat. However, there are a few extension candidates, so I ranked the top five in order of likelihood.

Mike Iupati Anthony Davis1. Mike Iupati (Free agent: 2015)

Iupati and Davis were drafted on the same evening back in 2010, only six picks apart. Since then they’ve played on opposite sides of the line but remain inseparable in the locker room. For those reasons it wouldn’t have been a surprise if extensions for both players were announced on the same day. If the 49ers are happy with Davis’ production, they have to be ecstatic about Iupati, who was named first-team All-Pro by both the Associated Press and the PFWA.

2. Anquan Boldin (Free agent: 2014)

He came to the 49ers in a trade from Baltimore with one year left on his deal at $6 million, and said he’d be open to working out an extension.

“I think any time you go somewhere, you don’t want to just be there for a year,” Boldin said. “You definitely want to know that you’re wanted. You want to feel like that’s home. You don’t want to feel like it’s just a stop.”

The 49ers won’t be handing out any Bam-like extensions to Boldin since he’s 32, but adding an extra couple years to the deal could both make the player happy and provide a little cap savings for the 49ers in the short-term. Assuming Boldin would take a deal that would pay him less than $6 million per year, that is.

Michael Crabtree 49ers3. Michael Crabtree (Free agent: 2015)

While both sides probably would like to work something out, especially with Crabtree feeling A LOT better about the team’s quarterback situation, it might not be particularly easy given the history involved. Crabtree held out until October of 2009, missing the first six games of his rookie season. Until the 2012 season, injuries have hampered his performance. However, after dealing with a minor setback early on in camp, Crabtree shined with 1,105 yards and nine touchdowns during the regular season and 285 yards and three TD in three postseason games.

The 49ers have struggled to find quality receivers in recent years, so there’s reason to believe they’d be motivated to keep Crabtree after a year where he was a top-10 player at the position. The only problem: the chances of Crabtree signing at a discount are slim and none.

4. Tarell Brown (Free agent: 2014)

He turned 28 in January, but the 49ers haven’t shied away from veteran corners since Vic Fangio took over the defense (example: Carlos Rogers). Brown was the fourth best cover corner in the NFL last season according to Pro Football Focus, and has missed only two games over the last five seasons. How likely would an extension for Brown be? The NFL Draft will probably be a good indicator — if the 49ers spend one of their early picks on a cornerback, they might be prepared to let Brown hit the open market.

5. Justin Smith (Free agent: 2014)

Smith may very well retire after the 2013 season, especially if the 49ers break through and win a Super Bowl for the first time since he joined the team in 2008. After all, Smith turns 34 in September, and if he plays in all 16 games in this upcoming season will have played an astounding 205 regular season games in his career. That’s a tremendous feat for a guy who takes (and gives) so much punishment as a defensive lineman. But if Smith feels up to it, the 49ers would probably like to employ him as long as he’d like to play. Remember, there’s no guarantee they’ll find his replacement in the Draft.