As to back on topic, it depends on what you want. If your goal is a farewell, feel good tour for Mauer, then take the safe route, which few will criticize, and give Mauer a one yr contract. Accommodate Joe Mauer and his fan base, but deprioritize winning. If, however, your goal is to compete at the highest levels, find a full time first baseman who moves you toward that goal. My personal option would be Donaldson at third, Sano at first. It might bomb spectacularly, but it also might succeed spectacularly. Mauer offers no such upside.