that's pretty much what a lot of us have said for the past few years in lieu of bonner. What bonner benefits the spurs in spreading the floor can easily be trumped by the hole filled by a competent defensive big. Hopefully, thomas can help (optimisim for a rookie) but still another role player big is paramount for getting the spurs on track to being an excellent defensive team again (leonard and green help too).
Blair is fun to watch, plays hard and is very athletic but he's too small for what the spurs need. Send him to a team that can use his talents and get some value back even if it's a pick, but the spurs have to find a true big (not an all star - just a role player) that can help fill the hole on defense. This isn't a knee jerk reaction - just common sense given the status and ability of the spurs front line. Splitter needs to play with duncan - can't do that with bonner & blair as the only reserves.