I was looking at WAR levels for first basemen. Casas' numbers align pretty favorably to Freedie Freeman with 3 notable exceptions. He's not hitting for as high an average, which we have already seen great improvement on since May. But the others are speed related - doubles and steals. Then I noticed Freeman's height and weight are 6'5", 220 lbs. Tristan's are 6'5", 245 lbs (and I think I heard him say he's actually at 265).
I said it once way upthread, but I hope he loses 20-30 pounds to improve his hitting, defense, and base running. I'll bet the team suggests it for this off-season too.