If you have him starting that day (b/c he was listed as a starter), then he couldn't pitch in relief also.

And if he wasn't scheduled to pitch and you had him benched, then you wouldn't get his stats, like anyone else on your bench.

But if you had him in your starting lineup (what I think you mean by "on your roster") even if he wasn't scheduled to pitch - like if you decided on 5 starters and just left them in your starting lineup, figuring you'd only replace one of them and use the 6th in certain spots - and he appeared in relief on a day he didn't start, then yes, you'd get his stats for that day but it wouldn't count as a game started against your 162 game max.

Hmmm.....some elements of strategy come into play here, don't they?