Tavon Young was supposed to be a key component of BAL's defense as slot corner - I believe he graded out very highly last year on PFF and Ravens signed him to an extension that made him one of the top paid slot corners in the league (if not the highest paid). However, the Ravens mitigated that by picking up Marcus Peters.Also, the great hidden strength of the 2019 Patriots (our relative and consistent health, despite the obvious exceptions) is also a strength of Baltimore's. Their IR'd players of greatest consequence have been two backup CBs (Tavon Young and Jimmy Smith) and their backup SS (Tony Jefferson, backing up Earl Thomas and Chuck Clark, and to a lesser extent Anthony Levine and Jordan Richards). That's borderline miraculous injury luck year-to-date.
BAL has lost their second best pass rusher - Pernell McPhee - for the year. They also lost their starting safety (Jefferson, although he wasn't playing well) and another back-up safety (DeShon Elliott, who was highly regarded).
Brynden Trawick is a special teams Ace who is out for the season.
BAL has suffered other injuries - Smith (for all but six plays), Hollywood Brown (who is supposed to be BAL's #1 receiver) and Patrick Onwuasor (who started the season as the MIKE but is probably better suited for the WILL), but they apparently will be back for NE.
Not terrible injury luck but they haven't remained unscathed. Fortunately for BAL, the unit that has received most of the injuries was their deepest unit when they began the season.