He played a lot early when Julio was injured. But he was just in at the end of the half and I expect you will see him have a big play sometime in the second half.
The final answer for all the "where's McCoy" questions is that there isn't one big pool of wide receivers to choose from, as it looks like a lot of people think. Mike is Julios backup, and we'll only see him out on the field if Julio isn't.