Mings was sold to Aston Villa this summer after a successful loan last season.
Asked if it was a surprise to see Mings called into the England squad, Howe said: "I don't think it was a surprise. I spoke earlier before our game against Aston Villa that for me he's got every attribute needed to play for his country.
"I'm really, really pleased for him on a personal level. Seeing how hard he worked here, coming back from the various injuries he had - fantastic attitude at all times to come back and achieve.
"Very sad from our perspective that it's not for us and it's for another club, but that's how it is. I'm just really pleased for him on a personal level knowing how hard he's worked to get there."