A comma in this situation is a matter of preference. Simple English sentences are structured as SVO -- subject verb object, and anything preceding the SV is usually offset by a comma. However, this rule is more important when the information preceding the SV is rather lengthy, and as a matter of personal preference, I find that some commas in this position can upset the flow of the sentence. I think that's the case with this sentence, and I'd leave the comma out. But this isn't a huge grammatical issue, and no one will think less of you either way.