OL plan a little confusing Dan Leberfeld

Rex Ryan has said repeatedly that he doesn’t want to play Vlad Ducasse at guard.
He wants him to focus on playing tackle.
Asking him to learn both guard and tackle is perhaps too much for the young prospect.
Okay, so why did Rex start him at right guard in Houston, after repeatedly saying he didn’t want to play him at guard anymore?
True, Brandon Moore was out, but why not start Zane Taylor or Robbie Felix at right guard? Or even Curtis Duron or Chris Stewart, two other guards on the roster. They all have guard experience.
Ducasse struggled mightily in Houston at right guard.
Rex, if you want to keep him at tackle, keep him at tackle.
The kid’s head is spinning right now.