Jackson has been absent for 16 straight practice sessions due to a sprained PCL in his left knee that has seen him not play since Week 13.
The 2019 NFL MVP has missed the Ravens' past five games, where they have gone 2-3 and scored 13 points per game, which is the second-worst record in the NFL.
Ravens head coach John Harbaugh has been reluctant to discuss Jackson's status over the past fortnight and simply replied "no updates at this time" when asked on Wednesday.
The situation is further complicated by top backup Tyler Huntley dealing with tendonitis in his right throwing shoulder. Huntley did not throw during the media portion at practice on Wednesday.
"He's doing a lot better," Harbaugh told reporters about Huntley. "He was out there in practice today and took a bunch of plays. I'd say he's on schedule, hopefully, and we'll see where it goes."
If Jackson and Huntley are both unavailable then undrafted rookie Anthony Brown, who has one career NFL start, would step in.
Ravens tight end Mark Andrews added: "You look at the two other guys [Huntley and Brown], there is so much trust in both of them.
"We know with whoever we put out there – Lamar, Snoop [Huntley] or AB – we'll be all right and ready to go."