LAKELAND, Fla. -- Riley Greene stepped to the plate Sunday against Twins starter Pablo L¨®pez and took three called strikes, all different pitches, in his first at-bat. He was unhappy -- not with the umpire, but with himself.

¡°I was like, ¡®Dang, I wasn¡¯t locked in mentally. I want to face him again,¡¯¡± Greene said.

Fortunately, starters are usually working into a second trip through the order by this point in Spring Training. Greene got his rematch in the third inning. He didn¡¯t chase fastballs just off the corners and took a 2-0 changeup that just hit the outside corner, but he was ready when a L¨®pez curveball hung over the outer half of the plate.

Greene crushed it to left, a 106.5 mph line drive off the wall on a bounce for an RBI double.

¡°I was locked in mentally and I hit a double,¡± Greene said. ¡°You can go at-bat to at-bat, and most of the time it¡¯s mental.¡±

Two innings later, Greene faced Tyler Mahle, shrugged off three consecutive splitters in the dirt for a 3-1 count, then crushed a high fastball even harder, a 109.5 mph liner that center fielder Michael A. Taylor ran down for a hard-luck out.

A day later and a few miles down the road, Greene hit another ball hard to left-center, this time homering against the Red Sox. He came back to Lakeland on Tuesday, connected with another high fastball off Cardinals prospect Gordon Graceffo and drilled a 108.1 mph double off the left-field wall at Joker Marchant Stadium. He worked a full count off Graceffo his next at-bat, fouling off a two-strike slider and a curveball, before pulling a 103.6 mph line drive that Cards rookie Jordan Walker somehow caught at the right-field fence.

Add in Greene¡¯s 417-foot home run off the left-center-field concourse against the Phillies at Clearwater last Friday, a drive with a 106.6 mph exit velocity, and he appears locked in. He doesn¡¯t just have seven hits in his past 16 at-bats; he¡¯s also hit eight balls in that stretch with an exit velocity of 103 mph or harder, seven of them line drives or fly balls.

For someone who had an above-average average exit velocity (61st percentile according to Statcast) but a well-above-average ground-ball rate (56.8 percent, compared to an MLB average of 44.9 percent since 2015) as a rookie last year, it¡¯s a big step. For someone who came to Spring Training talking about ¡°swing thoughts¡± rather than adjustments, it¡¯s a demonstration of the power of positive thinking.

¡°In my opinion, hitting is like 90 percent mental, having a game plan,¡± he said. ¡°It¡¯s hard to hit without a plan.¡±

Greene's plan brought him back to his strengths, some of which he got away from after he arrived in Detroit and moved into the leadoff spot last season. He¡¯s hitting through the ball with a better attack angle, creating backspin while looking to hit towards the middle of the field. That¡¯s the cavernous part of Comerica Park, even with the fences moved in, but it¡¯s the ideal direction in terms of swing timing.

¡°In [batting practice] and in my early work, I want to spin the ball correctly. I want true backspin,¡± he explained. ¡°I don¡¯t want topspin. I don¡¯t want a hook. I want true backspin wherever I hit it, because that means I¡¯m staying through the ball, swing is perfect. That¡¯s kind of what I look for. I just think homers to left-center field in BP.

¡°That¡¯s my goal, is the big part of the field, the gaps. I feel like it helps me mentally, and my swing will just follow if I think that. It¡¯s crazy to think having that mentality can really help your swing, but it does.¡±

Greene worked on this mentality all offseason at home in Oviedo, Fla., with Jered Goodwin, his high-school coach during his freshman season and now scouting director for Perfect Game. His hitting group included fellow Oviedo natives and good friends Ryan Mountcastle and Vaughn Grissom, along with Daniel Vogelbach. Together, they discussed their experiences and their approaches.

¡°He owned his offseason this year,¡± Goodwin said.

The results are showing. Greene has a few more weeks to keep building on his progress.

¡°If you make an out and you had a good process, I¡¯m totally cool with it,¡± he said. ¡°Even during the season, if I¡¯m right up here [mentally] and I struck out, whatever. What angers me is if I get out and I wasn¡¯t right up here.

¡°I just want to keep it the same, try to repeat, repeat, repeat, repeat, as much as I can. Just try to stick with it.¡±