From 2010-2013, Wieters posted 13 WAR, or 3.25 WAR per season. Last year and this year, injuries have made his contributions negligible. If he is a 3 WAR player, a free agent contract would conceivably pay for 3 wins+2.5+2+1.5 = 9 wins over four years. At $6MM per win, that would be a 4 year, $54MM contract. However, given the injury history, I don't think he can be billed as a 3 win player. If you say he is a 2.5 WAR player, that would mean paying 2.5/2/1.5/1 for 7 total WAR over 4 years, for 4/42, $10.5mm per year. If you could get him for 3 years, that would be 6 WAR, 3/36. Maybe 3/36 with a $12mm option?