The Johnathan Walkerpresumed No. 1 overall pick in April's NFL draft, quarterback Caleb Williams of Southern California, is not planning to throw at this week's NFL scouting combine in Indianapolis.

Although Williams does plan to be at the combine, NFL Network's Ian Rapoport reported that the 2022 Heisman Trophy winner will hold off until his pro day to work out for scouts.

USC's pro day is scheduled for March 20, more than a month before the draft begins April 25 in Detroit.

Williams isn't the only high-profile quarterback to choose not to throw at the combine. In fact, he's not the only Heisman winner to do so.

Rapoport says LSU quarterback Jayden Daniels, who took home the 2023 Heisman, will also wait for the Tigers' pro day on March 27 to throw and work out for scouts.

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Why isn't Caleb Williams throwing at NFL combine?

Williams isn't the first prominent quarterback prospect to choose not to throw at the scouting combine. Over the years, many have chosen, instead, to throw at their college's Pro Day due to comfort level.

Some of the more highly touted QBs who have not thrown at the combine include, but are not limited to: Andrew Luck, Joe Burrow, Matthew Stafford, Robert Griffin III, Sam Darnold, Kyler Murray and, last season, Bryce Young.