What free agent guards are available?

Now that Evan Mathis and Todd Herremans are gone, who will the Eagles replace them with? You know about Allen Barbre and Matt Tobin and the UDFAs the team picked up this spring, but the odds are the team will acquire one or more guards on the open market.

The best possibility might be a veteran we don't know about, who will be cut at the end of training camp.  Seems crazy but it worked great at kicker last year.  The Eagles came within days of getting stuck with Alex Henery, whose deterioration continued until he missed 3 field goals in one game for Detroit -- just 38 days after the Eagles let him go. Instead, the rkey when Indianapolis cut him, and he set the NFL rookie record for points.

• Obviously you can't count on that kind of luck, and the Eagles need to kick the tires on the existing free agents.  Here is a list by Adam Caplan.  Not only is he a knowledgeable football analyst, but he has close connections with the Eagles, so there is a good chance that his list is very similar to Ed Marynowitz'.

Best available guards: Justin Blalock, Charlie Johnson, Davin Joseph, Rob Sims, Dan Connolly, Kevin Boothe

— Adam Caplan (@caplannfl) June 11, 2015

Some thoughts:

These are all NFL veterans around 31, most with over 100 starts.  Most are left guards, while the Eagles' need seems to be larger at right guard. It's worth remembering that Todd Herremans re-signed quickly and these guys were passed over, so it's probably wise not to get your hopes up. Most of them have declined noticeably in the last year or two.

Justin Blalock LG, 31, 6'4", 326, 125 starts

PFF considers him an excellent pass blocker (+7.5, despite giving up 5 QB sacks and 5 QB hits) but a -2.6 run blocker -- the 23rd best guard in the league by their subjective standard, right behind #22 Todd Herremans..  For comparison, PFF considered Evan Mathis the best guard in football, despite giving up 6 QB hits and 2 sacks. Their love of Mathis is a bit of an outlier though.

He's not a good fit for the Eagles' zone blocking scheme though, with a 40-yard-dash time of 5.10, a 3-cone of 7.75 and a 20-yard shuttle of 4.72 -- back in 2007.  In fact, the Falcons released him as they switched to an outside zone blocking scheme under new coordinator Kyle Shanahan.

Charlie Johnson LG, 31, 6'4", 305, 115 starts, Super Bowl victory

Johnson plays both guard and tackle, which might make him an attractive depth addition, though he missed the final 2 games of 2014 with an  injury.  PFF ranks him #52, not quite as bad in run blocking (-3.5) as in pass pro (-5.0), with 4 QB sacks and 8 QB hits. Zone blocking experience.

Davin Joseph RG, 31, 6'3", 313, 112 starts, 2x Pro Bowl

Character! Joseph is very active in charity work and has won several awards, including the Byron "Whizzer" White award. Though he gave up only 3 QB sacks and 7 QB hits, comparable to Blalock and Johnson, PFF's raters hate him with a fierce and malevolent passion. He's ranked 80th of 81 guards, with a pass pro score of -32.8 and a relatively kind run blocking score of -24.2. He has zone-blocking experience, though.

Rob Sims LG 31, 6'3, 312, 114 starts

Sims is -- or at least was -- athletic enough for a zone blocking scheme 5 years ago. PFF rates him 37th overall, solid on passing downs at +2.0 -- 1 sack, 5 QB hits -- but  terrible in run blocking (-5.5).

Dan Connolly RG, 32, 6'4", 305, 71 starts, Super Bowl victory

Connolly is not especially athletic but once ran a squib kickoff back 71 yards for a touchdown, setting the NFL record for OL kick return.  He was a captain on last years Super Bowl-winning Patriots team.  PFF thinks he's fine on runs (+1.3) but very bad in pass pro (-16.1).  By their count, he gave up 3 sacks and 12 QB hits.

Kevin Boothe LG, 31, 6'5", 325, 62 starts, 9 games and no starts last year..

PFF has him as a passable -0.9 on passing downs (3 sacks, 5 QB hits) but a rough -4.5 on runs.

Gabe Carimi, T, 26, 6'7", 314, 26 starts

Carimi would be a high-risk, high-reward backup choice.  Anthony DiBona calls him "a first round bust" who played well at guard for  few games in 2012, though he has usually played tackle -- badly. Zach Berman notes that he's "not an ideal fit for a zone-blocking scheme" but played in Chicago when two current Eagles execs worked there, so they've had a chance to observe him up close.

Other possibilities:  Chad Rinehart? Mike Pollak? Jerome Clary? Daryl Colledge? What do you think?

EDIT: Added more detail on zone blocking fit, athleticism, etc., based on THEGREATJB99's suggestion.

EDIT2: Brawnybalboa caught a mistake, Connolly didn't score on the 71 yard return., Added Zach Berman's suggestion of Carimi, too