Jake Long signs with St. Louis Rams

Jake Long needs to answer questions about his injury history in St. Louis. (Kellen Micah/Icon SMI)

Jake Long ended his lengthy free-agency flirtation with the Rams late Sunday night, signing with St. Louis for four years at a reported $36 million, with up to $20 million in guaranteed money.

That's $10 million less in guaranteed dough than Long received on his rookie deal as the No. 1 overall selections in 2008, back before the NFL limited the contracts handed out to draft picks. The $36 million St. Louis gave Long also is reportedly about $1 million per year more than Miami offered its former left tackle -- turning this situation into a huge swing and miss for a Dolphins team that has been very active in free agency thus far.

Miami now faces a 2013 with Jonathan Martin back at left tackle after he was severely overmatched during the 2012 season. Martin coughed up six sacks and a staggering 47 QB hurries between his time at RT and LT, the most of any lineman in the league, per Pro Football Focus.

The success of this addition for St. Louis, meanwhile, hinges mostly on Long's health. Long was a Pro Bowler from 2008-11 (though you could debate that final honor), but his performance dropped off rather quickly over the past two seasons, as he dealt with a long list of injuries.

The Rams did put Long through a lengthy physical examination last week, and their $36-million offer indicates that they're pretty confident in his health.

Dropping Long into their lineup will allow the Rams to slide Rodger Saffold either to right tackle or a guard spot -- according to a report from Newsday's Bob Glauber, Saffold was planning to ask for a trade if Long signed and kicked him to RT. A healthy Long would be an upgrade at Saffold on the left side; keeping both in the starting five up front would be a boon for QB Sam Bradford.

St. Louis has not been shy about throwing money around so far this offseason, adding Long's $36 million to the $38.5 million (and $19 million guaranteed) given to tight end Jared Cook. Both players are capable of elevating the offense beyond its previous form.

The Rams are hoping Cook can finally realize his potential. But everyone in the NFL already knows where Long's ceiling is. It's just a matter of whether or not he can reach those heights again.

Grade: B-plus.