Thomas Wasn't Far Behind, Earning a 92.5 PFF Grade After Also Putting Together a Solid Debut

Two undrafted Minnesota Vikings rookies are making a strong impression early in the NFL preseason, with both defenders earning standout grades in their debuts. Linebacker Jacob Roberts and safety Jacob Thomas, neither of whom was drafted, are suddenly players worth watching as the preseason continues. Roberts was especially impressive, earning a 92.6 PFF grade, making him the highest-graded undrafted free agent during the opening week of the preseason.

He was effective against the run and in coverage, posting a 75.8 run-defense grade and a 91.4 coverage grade. He also didn't miss a tackle, recorded two defensive stops and picked off a pass in coverage. Thomas wasn't far behind, earning a 92.5 PFF grade after also putting together a solid debut.

Like Roberts, he avoided missing a tackle and came away with an interception. Thomas' coverage work was strong, earning a 91.6 PFF coverage grade. PFF's Gordon McGuinness ranked Roberts and Thomas among the best rookies in the NFL so far, with Roberts coming in at No. 3 and Thomas at No. 4 after the first week of the preseason.

For Minnesota, that's a great development. The preseason doesn't settle roster battles by itself, and both rookies still have more work to do. But interceptions, clean tackling and strong coverage grades are difficult to overlook.

Neither player needs to become a star overnight, but performances like these can go a long way toward earning additional time on the field. The Vikings have lots of established players expected to make an impact this season, but these two young defenders are making a strong case for themselves early on. Both players made the most of their time in their NFL debuts, and the Vikings suddenly have two young defenders worth watching as the preseason continues.