Jones is being paid 8 million AAV, which some fans say is too much, and I can't say I disagree. However, he is an important piece to this defensive core. When Seth is on the ice, the Hawks are 4-3, with a 2.36 GAA when on 5v5. Without him, they're 2-3-3, with a 3.06 GAA on 5v5 play.
Granted, Seth isn't the best defenseman, but it sure does help to have him out on the ice. They'll wait another 7-10 days to reevaluate the injury.