With NFL training camps kicking off ahead of the 2023 season, it's only a matter of time before serviceable veterans still lingering on the open market get snapped up. Practices will reveal roster inadequacies and injuries will rear their head, leaving teams scrambling to bring in suitable free-agent replacements.

These vets may not be superstars, but they have the talent and potential to contribute to a winning team. With that in mind, here is a look at five of the most underrated free agents still available heading into training camp.

Bryce Callahan, CB

Injuries have been the unfortunate story of Bryce Callahan's career, but the 31-year-old cornerback was relatively healthy last year and could be a solid contributor in 2023.

The 5'9", 188-pound defender went undrafted out of Rice in 2015 but still managed to earn playing time with the Chicago Bears as a rookie and remained with the organization for four seasons. After a two-year stint with the Denver Broncos that was also marred by injury, Callahan caught on with the Los Angeles Chargers for the 2022 season.

He was a boon for the Bolts, starting 11 of the 15 games he was available for. He earned a decent 64.2 Pro Football Focus grade in those contests while besting or matching his previous career highs in interceptions (three)—one of which was returned for his first career score—tackles (47) and pass defenses (six).

He may be a tad undersized, but Callahan still displayed enough speed and athleticism last year to be a competitive defender. He hasn't worn too much tread off his tires after missing so many games, having logged a meager 3,744 defensive snaps in 81 games across seven seasons. If he can avoid missing extended periods again this year, he'll likely be a nice pickup for a club willing to roll the dice.