At the conclusion of the pre-draft process, Clark was projected to be a sixth to seventh round pick or to go undrafted by NFL draft experts and scouts.

[5] "A team captain and three-year starter at Virginia Tech, Clarke [sic] is an interchangeable safety and reliable run-defender with average size and above-average length.

[12] Head coach John Harbaugh named Clark the third free safety on the depth chart, behind veterans Eric Weddle and Lardarius Webb, to start the regular season.

Head coach John Harbaugh named Clark the primary backup free safety, behind Eric Weddle, to begin the regular season.

[19] On December 2, 2018, Clark earned his first career start after Tony Jefferson sustained an ankle injury the previous week and remained inactive for two consecutive games.

In Week 14, Clark recorded four combined tackles (three solo), deflected a pass, and made his first career interception during a 27–24 loss at the Kansas City Chiefs.

Clark intercepted a pass by quarterback Patrick Mahomes, that was intended for wide receiver Tyreek Hill, and returned it for a five-yard gain in the second quarter.

[22] On January 6, 2019, Clark appeared in his first career playoff game as the Ravens lost 23–17 to the Los Angeles Chargers in the AFC Wild Card Round.

[24] In week 13 of the 2019 season against the San Francisco 49ers, Clark made a team high 7 tackles and recorded a strip sack on Jimmy Garoppolo that was recovered by teammate Brandon Williams in the 20–17 win.

[26] During the 2019 season, Clark took over the role of communicator of the defense when he was selected to be the lone player with the headset in his helmet to relay play calls to his teammates.

[29] In Week 9 against the Indianapolis Colts, Clark recovered a fumble forced by teammate Marcus Peters on running back Jonathan Taylor and returned it for a 65-yard touchdown during the 24–10 win.