what potts said.
come 40, you'll be highly sought after by alot of the eastern europe BBB teams that'll be capped at 21.
plenty of 2nd year teams will be looking for LBs with good SPD/AGI/VIS in the lvl. 16-21 range.
if you don't have your boosts left, there's a good chance you might be a back-up, but even then, you might be able to find shot at starting. many of the lvl. 20-21 LBs that will be out there will have crap builds (otherwise teams wouldn't have let them go), so a well-built lvl. 16 can be a hot commodity.
i brought in a lvl. 17 LB for one of the 21-caps last off-season. he ended up starting all season for a 16-0 team.