Since his last call-up Miller is only 3-for-14 but he does have three walks and, most importantly, 3 K's in 17 plate appearances. That's huge improvement from before when he was striking out 50% of the time. He's either walked or put the ball in play in 14 of 17 PA's and that's definitely progress. He also is showing some pop as he has a HR and a double in those three hits.
I think it was the game against the White Sox where he hit a change-up on the outside corner at the knees over the center field wall. Then he got jammed and hit a fly ball to the warning track in right. I remember thinking, "Damn, this kid has more pop than your typical middle infielder".
Mercado is hitting .262/.744 the last 30 days. Those are better numbers than Harold Ramirez, Zimmer, and Naylor have put up this year. Also better than Eddie Rosario (.254/.685). If Oscar can keep it up we may just have something when you factor in his range in the OF and speed on the bases.