Long, the first overall pick of the 2008 draft by the Miami Dolphins, spent a few days in St. Louis last week and passed a physical, but left without a deal. Kevin Demoff, the Rams' chief operating officer, confirmed the signing.
Long is the Rams' second acquisition in free agency along with tight end Jake Cook, who got a five-year deal. St. Louis took standout defensive end Chris Long, who has 24½ sacks the last two seasons with the second overall pick of the '08 draft.
Long started every game his first three seasons and has been to four Pro Bowls, but has been injured at the end of the last two years. He finished 2012 on injured reserve with a left triceps injury and the Dolphins declined to give him a franchise tag and pay him $15.4 million next season.
At a news conference to introduce Cook last week, coach Jeff Fisher scoffed at a report quoting the agent for incumbent left tackle Rodger Saffold saying his client wouldn't be happy moving to the right side, saying he had talked with Saffold.
The Rams picked up center Scott Wells in free agency last year.