Doran has played 6/7 and 9 for the 19's over the last 3 seasons. As has been pointed out he certainly doesn't look like a half back but has a turn of pace that would surprise many.
Clever player and wouldn't let Wigan down.

That's why I would play him from the bench. He can cover any of those positions if Wane decides to give Williams a rest.

I think the 19 picked for Friday is done with fingers crossed with regard to players fitness.
In this evenings M.E.N, the article after announcing the inclusion of Doran in the squad goes on to say that Rob Lever, Ben Austin and Oliver Gildart are on standby to face table topping Saints.
Then Wane is quoted as saying "I would loved to have Lockers, Mickey Mack and Faz out against these and give it a real physical dig". That comment to me sounds as if Lockers is out already.
He mentions quite a few things about how it will be a very young team, maybe someone can post the full statement.

A full back/winger on the bench, why?

Agree with others. Doran has guided the 19s around consistently well from in the last couple of months. I would sooner see Jamie than someone else playing out of position. It would be a hell of a challenge but he may prove a surprise package if called upon.

No, don't misunderstand me. My point is that the negativity is counter productive. James may not be the best prop in the team but usually it is better to play him than an injured other. Wane also seems to see some galvanizing quality in him in training. When we have other bodies back he can take on his intended role. Otherwise we will have to overplay the young lads. Given the nature of the SL competition that makes him important to our set up. Any more injuries and Bostonslugholes might be getting the phone call from Wane.

How long are you going to cling on to that one for?

exactly...except i would start him at 6 or 9

I think you must have misunderstood me then, negativity?? Anyway were going off topic now I would gladly put my boots on for one last shindig