Tanard Jackson was lining up with the third string so the Redskins weren't really counting on him but his suspension still leaves ripple effects.
Although the NFL’s statement called the action an indefinite suspension it seems more likely that it is a lifetime ban. Jackson has already served suspensions of four games and one year when he was with the Bucs and the indefinite suspension after he came to the Redskins. That one ended up being two years. The NFL is unlikely to give him a chance to earn a fifth suspension. Even if the NFL did let him come back at some point it’s hard to imagine a team signing a player with his history.