They'll likely do what they can to ease him into moving on it... lots of hand walking and they may even resort to some of the mild herbal sedatives to keep him from exploding when they unhook the lead line the first time.
I'm surprised too, that they describe him as still getting a rather high power diet including three rations of grain and alfalfa. I'd think they'd be keeping his energy food down while he doesn't need it. I'd think some good bland grass hay and minimal grain. I'm sure they've reduced the amount of grain, if not the frequency, from what he would have gotten when he was running.