The Ravens began training camp Thursday without Flacco, who told the team of a disc issue in his back just before the first full-team meeting. He is expected to miss at least a week.
Olson, who worked out for the Ravens on Thursday, likely will have a temporary role right with Flacco sidelined, joining Ryan Mallett and Dustin Caughan as quarterbacks on the roster. Mallett has taken Flacco's spot with the first-team offense and Vaughan is a second-year player out of Division II West Texas A&M.
With a quarterback short at the first practice of camp, the Ravens used offensive assistant coach Matt Weiss to line up under center and hand off to running backs in drills.
We have signed former Clemson QB David Olson.— Baltimore Ravens (@Ravens) July 28, 2017
This season is expected to be a bounce-back year for Flacco, who has gone 29-29 since winning the Super Bowl in 2012. He has thrown 80 touchdown passes, but 61 interceptions -- third most in the NFL -- over that four-year span.
Coach John Harbaugh likely will bring in another quarterback and is considering Colin Kaepernick, who opted out of his contract with the San Francisco 49ers on March 3. Kaepernick has been a polarizing figure for his refusal to stand during the national anthem prior to games last season.
"He's a really good football player," Harbaugh said of Kaepernick after practice Thursday. "I believe he's a really good person. It all depends on a lot of things. It depends on Colin first of all and what's his passion, what's his priority, what's he want to do, what kind of shape he's in. So we'll just see where it goes. I don't think it's different for us than any other team."
Olson played under Harbaugh's brother, Jim, at Stanford. For his senior season, he transferred to Clemson and most recently played for the KC Phantoms of Champions Indoor Football.