Millwood, 36, had been signed by the Yankees earlier in the year, but opted out of his contract when the Yankees proved reluctant to call him up after two unimpressive starts with Triple-A Scranton Wilkes-Barre during which he allowed three home runs in just nine innings. Millwood was a regular member of the Orioles' rotation last year, putting up a 5.10 ERA over 31 starts with a 4.46 xFIP.
On a minor-league contract, Kevin Millwood isn't much of a risk for the Red Sox, but I don't think he really solves either of their problems. If they don't let this signing stop them from making any other necessary moves, then it's not a problem. But if they try to stick with Millwood just because they have them, then they could end up waiting way too long to fill holes that need filling.