Yes I agree, although if the contract was only for say two years instead of four, those two seasons may be spent by him looking on from the stands while serving a two year ban.
I just can't see why the club would bother with someone of his standard, regardless of the term of his contract - there doesn't appear to be much upside from getting him, but a lot of potential downside.
If the club is really considering him, I'm concerned that they've been drawn in by the general local complacency about the WADA outcome, and this apparent local view that the players will either still get off, or only be banned for a few weeks or so.