The team later confirmed that Griffin will be back in 2019 on a two-year deal.
The 29-year-old veteran appeared in three games for the Ravens last season, including a key December game in Kansas City against the Chiefs when he took over for an injured Jackson late in the game.
In 2016, Griffin started five games for the Cleveland Browns. The team went 1-15, with Griffin leading the Browns to their only win that season against the Chargers.
Griffin did not play at all in 2017, but the Ravens were impressed enough with him last off-season to sign him to a deal. He played well enough in the preseason to earn the third quarterback job with the team.
Griffin was a highly-touted prospect out of Baylor University, and was the second overall pick by the Washington Redskins in the 2012 NFL Draft.
He was the NFL Offensive Rookie of the Year in 2012 and led Washington to the postseason, but was injured in Washington's wild-card loss to the Seattle Seahawks.
Griffin lasted three seasons with the Redskins, going 14-21 with a quarterback rating of 90.6.