ESPN's Mel Kiper Jr. noted teams would be looking closely at Darnold's ability to show leadership skills, clean up his mechanics and make every throw from every situation (under center, three-, five- and seven-step drop).
USC head coach Clay Helton defended Darnold's leadership skills during an appearance on the NFL Network:
Reign of Troy captured Darnold's first snap of the day, which he took from under center and threw a simple five-yard route to the hashmark:
USA Today's Michael Schwartz highlighted Darnold's ability to put air under his throws and place the ball right in his receiver's hands:
Ryan Abraham of USCFootball.com posted two videos, with one showing Darnold's scrambling skills and the other coming as rain began to fall on the field:
Heavy rainfall continued to come down throughout Darnold's workout, which Bruce Feldman of Fox Sports noted may have worked in the USC star's favor:
The weather didn't do anything to hurt Darnold's accuracy when he threw the ball deep down the field:
Cleveland Browns head coach Hue Jackson was among the notable attendees at USC, per Jennifer Lee Chan of Niners Nation:
Trojan Sports added Browns general manager John Dorsey and offensive coordinator Todd Haley were also present.
There was also another prominent Browns executive in the stands with Darnold's parents:
The Browns own two of the top four overall picks, including the No. 1 choice, so it wouldn't be a surprise if Darnold is high on their list of candidates to play quarterback in 2018.
Speaking to the NFL Network about performing in the rain, Darnold felt it was beneficial to showcase his talent in less than ideal conditions.
"I knew I was going to come out here and do well," he said, via 92.3 The Fan's Daryl Ruiter. "I think having played games in the rain before, I knew I wasn't going to have a problem with it"
After Darnold finished his workout, ESPN.com's Pat McManamon was optimistic about the quarterback's overall performance.
"Based on observing his pro day on TV, Sam Darnold did nothing to hurt himself and did plenty to help himself," he wrote. "With Tyrod Taylor in place, I continue to believe he's going to be the No. 1 pick in the draft."
Last season wasn't the banner year Darnold was hoping for. He was tabbed as a preseason favorite to win the Heisman trophy, but a slow start with 12 touchdowns and nine interceptions through six games dashed those hopes.
He finished well with 14 touchdowns and four interceptions over the last eight games, helping USC win the Pac-12 title for the first time since 2008.
The last game of Darnold's college career was one to forget with no touchdowns and one interception in a 24-7 loss against Ohio State in the Cotton Bowl.
Despite a lackluster season overall for one of the draft's top quarterback prospects, scouts remain high on his potential coming into the NFL.
B/R's Matt Miller has Darnold as his top-ranked quarterback and No. 5 overall player in the 2018 draft class.
NFL.com draft analyst Daniel Jeremiah compared Darnold's skill set and potential to that of former Dallas Cowboys quarterback Tony Romo:
"Darnold's a little bit taller than Romo, but they have a similar build. Like Romo during his playing career, Darnold is a really good athlete and is outstanding with his creativity when the play breaks down. Every now and then, both of them press their luck and make an ill-advised throw, but they each have rare playmaking ability."
Darnold's pro day was in a controlled environment, though nature did its best to throw an obstacle in his way. The 20-year-old weathered the storm and appears to have cemented his status as one of the top prospects in this year's draft class.