replace full name with last name comma space first name etc.

Col A contains full name. Might be Bob Smith and might be Robert Smith Jr. or Carol De La Cruz. Regardless, I need to put anything after the first space first, with a comma, then the first name last. So Bob Smith would be Smith, Bob and Carol De La Cruz would be De La Cruz, Carol and Robert Smith Jr. would be Smith Jr., Robert.

So far I have this:
=MID(A2&" "&A2,FIND(" ",A2)+1,LEN(A2))

It works, but I have no comma and space before the first name. What am I missing?