With Scales gone, you have an open defense spot in your training program, no? (Once you are out of the cup and can safely return to the 5-4-1 in friendlies) Seems like it would be worthwhile to plug Reg into that empty slot, as there has to be a decent chance he'd be inad by the end of the season.
FWIW, having played around with the toward middle instruction, I don't think Reg will be able to help you there with his current weak stamina. The possession boost you would get would be minimal at best, and it kills your attack on his side. Once his stamina is at least passable, then he'll make a great toward middle winger, but for now, I think he's just a regular/offensive guy (albeit a real good one
).