Eastern Illinois didn't have a pro day of its own, so Garoppolo traveled to take part in Northwestern's.
According to Eric Edholm of Yahoo.com, the private workout came about when Harbaugh introduced himself to Garoppolo and asked, "Wanna throw a little?" Garoppolo went on to throw for Harbaugh in an "off-limits-to-others part of the field," and the two spent about 45 minutes together.
Harbaugh later gave some of his thoughts on Garoppolo's workout to Yahoo.com: "Quick release, yes, but sometimes too quick. You want to see him go through whole motion."
Garoppolo -- who measured 6 feet 2¼ and 226 pounds at the NFL Scouting Combine -- is the No. 5 quarterback on NFL Media draft analyst Mike Mayock's positional top-five rankings. Garoppolo had strong showings at the East-West Shrine Game and Reese's Senior Bowl, and seemingly has moved his way into potentially being drafted as early as the second round. Former Indianapolis Colts GM Bill Polian has said he thinks Garoppolo could move into the first round.
San Francisco has only two quarterbacks on its roster, starter Colin Kaepernick and backup McLeod Bethel-Thompson, and it wouldn't be a surprise if the 49ers selected one in the draft. The 49ers used a second-round pick on Kaepernick in 2011 after Harbaugh put him through a private workout that included a throwing competition between the two.
As for Houston, while Garoppolo isn't in play to be the top overall selection, he potentially could be a second-round pick for the Texans should they choose a defensive end, outside linebacker or offensive tackle with the first pick.
Garoppolo was named the FCS player of the year after throwing for 5,050 yards and 53 touchdowns in 2013. In 2013, Garoppolo broke single-season school passing records held by Dallas' Tony Romo, and he also broke New Orleans Saints coach Sean Payton's school record for career completions.
Eastern Illinois' coach in 2013 was Dino Babers, who since has been hired at Bowling Green. Babers was Baylor's wide receiver coach when Robert Griffin III was the Bears' quarterback, and Babers said this season he never has seen a quarterback with a quicker release than Garoppolo.
Mike Huguenin can be reached at firstname.lastname@example.org. You also can follow him on Twitter @MikeHuguenin.