unusual choice of recommenders question

Agree with everyone here...I think you should definitely mention this in the optional essay to make your intentions clear. I would think this should help at the very least to deliver a clear message (as opposed to the adcom wondering negatively why you wouldn't ask a current supervisor)

Thanks for the replies. I read on the Wharton s2s site that an explanation is not necessary (posted by a current student). So, I was not sure.

As for getting a recommendation from my manager's manager, I have worked with him on a few projects and he knows me very well. So, I think I am ok there.

Just out of curiosity - how long have you been with this current employer? How long ago did you work with the managers who are recommending you?

Personally, I would not waste much precious essay space on the topic - the LORs will speak for themselves.

I asked a similar question to a few ADCOMS - in my case, I have been on a new, unorthodox assignment for a short time, and getting my current manager to write an LOR would result in something "incomplete". Generally, all the schools I asked said it was very common for applicants being afraid of antagonizing their current bosses, and it would not be held against them. The only school that even thought it was an issue was Stanford, and they simply wanted a submitted statement as to "why".