The wideout was released by the Philadelphia Eagles this offseason after two disappointing seasons that saw him appear in just eight total games due to injury and catch 23 passes for 395 yards and three scores.
In his prime, Jackson was one of the most dangerous deep threats in football. The three-time Pro Bowler has posted five seasons with at least 1,000 receiving yards and seven seasons exceeding 900 receiving yards.
He's also posted 17.4 yards per receptions over his career, twice averaging more than 20 yards per catch in a season.
The question for Los Angeles is whether Jackson still has the ability to take the top off a defense with his speed. He's now 34 and has missed 28 games over the past three seasons. He hasn't played a full season since 2013 (though he played in 14 or more games three times in that time period).
If Jackson can stay healthy and hasn't lost a step, he'll be an interesting weapon for the Rams. If he can't, he's a relatively low-risk addition, making him a gamble worth taking.