I'm not worried about injuries. However, a player with proficient GS is usually quite a bit better than an equivalent player with respectable GS. For comparable players, I would go with DMI to determine who should start - it usually gives a good indication just how much the skills are boosted.
DMI is really useless when determining who is "the better player" for players who have vastly different skillsets though - it's a really rough measure. But when one is just a stronger, but out of shape version of the other, GS can help you determine who is stronger right now.