Okay, but that ain't going to happen.
It's possible he'll last through spring training, and the season will begin with him in the starting lineup, Casilla on the bench, and Flaherty in the minors. But the team won't be able to hide him as a starting 2B and presumed leadoff hitter the way they were able last year to hide Kevin Gregg, another terrible player with a massive contract. But after a month of Roberts batting south of .200 and playing bad defense, the team will have to make a move.
And that's presuming he stays healthy, which is presuming an awful lot.
I don't see any reason to view Roberts' presence on the roster right now as anything more than a mix of a charity case and an organizational decision to add another mascot. I'm looking at the roster and the team's season as though he doesn't exist.