That would be fair interpretation if we weren't discussing Jose Mourinho, but given he has previous for throwing his players under the bus following a poor performance (at every club he has ever managed might I add) do you not think it more likely that the following is equally, if not more viable?
My personal interpretation of this announcement is that he simply wished to say that we have all been complaining about Sanchez's performances since t day he was purchased, and it is high time Martial replaced him in the starting lineup, but when he does eventually replace him, his performance was just as bad if not worse than Sanchez has offered before him (I disagree with Jose, I thought Martial, although nothing special, showed more attacking intent in his time on the pitch than any other United player)