On the surface, it's easy to understand why the Flyers would call up Walker: They're on the West Coast and they only have six defensemen. They need another guy as insurance.
But dig a little deeper and you'll see that this is the stupidest risk they could possibly take. It has nothing to do with Walker's status as a not-very-good NHL defenseman, but it has absolutely everything to do with his $1.7 million salary. The fear here isn't that Walker will be back on the NHL roster. The fear is that he'll be claimed on re-entry, and thus, the Flyers will be forced to pay half of his cap hit, against their own cap, for the remainder of his contract.
Walker has two years left on his contract at $1.7 million against the cap per season. Should he be claimed, the Flyers will be forced to pay $850,000 against the cap for the remainder of the current season, as well as next season. Once players come off of long-term injured reserve, that's not a number the Flyers will be able to handle against their cap.
I'd say the chances of Walker getting claimed are about 50/50. At $1.7 million, Walker is essentially untouchable with a ten-foot pole. Nobody will take that chance. But at $850,000, which is about the going rate for a sixth-or-seventh NHL defenseman, you can bet there are teams out there that need the help. The Buffalo Sabres, Anaheim Ducks, Montreal Canadiens and Winnipeg Jets all come to mind, and that's just off the top of my head.
I understand the need for a seventh defenseman. It's really, really important actually, especially when you're all the way across the country. We don't know what other options Paul Holmgren exhausted -- perhaps he tried to work a trade, which would also help explain losing Andreas Nodl on waivers, but couldn't swing anything.
Fine. Even in that situation, though, Walker isn't the smartest call-up. If you're going to risk the chance of paying salary against the cap for players that aren't on your team, you want to make sure that risk is as small as it can be. It'd be one thing if Matt Walker was far and away a better defenseman than the other options at Holmgren's disposal, but Oskars Bartulis is not any worse than Matt Walker. Maybe a little bit. The gap isn't that big.
Meanwhile, Bartulis also has a much more manageable salary. He makes $600,000 against the cap over the next two seasons, so if he were to be claimed on re-entry, the Flyers would only owe $300,000. That's a huge difference as compared to what they'd owe if Walker were to be claimed.
Let's just all hope and pray nobody claims Walker in the next 24 hours. The Flyers have taken yet another very silly risk here, and we'll have to hope it doesn't bite them in the ass.
Further Reading: Matt Walker on reentry waivers: What could go wrong?