Nick Castellanos exercises opt-out clause in deal with Cincinnati Reds to become free agent - ESPN
Nick Castellanos Free Agent Case: Not Your Typical Story of Splits
Nick Castellanos Loses 2021 MLB Hank Aaron Award, Rejects Cincinnati Reds Qualifying Offer, in Cincinnati Sports News
Ask Hal: Will Nick Castellanos opt out of contract, or stay with Reds?
Reds' Castellanos returns to ballpark where he's comfortable
Coming off a career year Nick Castellanos is going to get paid - Beyond the Box Score
Nick Castellanos set to reject Reds qualifying offer (report)
Report: Nick Castellanos 'Likely' to Opt Out of Reds Contract, Test MLB Free Agency, News, Scores, Highlights, Stats, and Rumors
Reds Sign Free Agent Nick Castellanos, by Jamie Ramsey
Reds' Castellanos returns to ballpark where he's comfortable