A's manager Bob Melvin could probably talk about Marcus Semien forever and still not run out of superlatives.

Oakland's shortstop is one of the hardest workers in all of baseball, as evidenced by his massive improvement defensively over the past few years. This season, Semien has taken his offensive production to another level as well.

The 28-year-old is slashing .280/.365/.443 with 10 home runs, 36 RBI, and 48 runs scored. He's on pace to set career-highs in nearly every major offensive category, including hits, walks, runs, and RBI.

"He's just become a complete player," Melvin praised. "Offensively, defensively, he's got leadership qualities, he's out there every day. There are a lot of things to like about Marcus Semien. He continues to get better and I don't see that slowing down either. He's very aware of what he needs to work on and what it takes to get better.

"Nobody works harder."

It probably seems crazy now, but Oakland actually entered the season without a set leadoff hitter. That changed in a hurry, as Semien grabbed the role and didn't let go.