MESA, Ariz. -- In the decade since Miguel Tejada departed as a free agent, the Oakland Athletics haven’t found a stable answer at shortstop. After a promising start to his career, Bobby Crosby got hurt. Cliff Pennington was a nice utility player, but he was stretched as an everyday answer. Spending a few million on Hiroyuki Nakajima from the Japanese leagues in 2013 didn’t turn out well. Trading for the Astros’ Jed Lowrie gave them a two-year patch they could contend with, but his slow reactions and poor range to his left made him an imperfect as well as a temporary fix.

So with that in mind, the A’s acquisition of Marcus Semien in the four-player package received from the White Sox for Jeff Samardzija was very much a case of trying to find a more lasting solution at short. While he was coming up through the White Sox organization, Semien was moved around the infield, starting primarily at short but playing second and third as well; that continued last year in the majors.

You could almost automatically understand the A’s interest given his .374 OBP and .839 OPS in the minors. But the other key consideration for the A’s is that they’re sold that he’s a shortstop.

“We knew with the hole at shortstop with Jed leaving, defense was going to be a priority,” assistant GM David Forst said. “Marcus is a guy who has played all three positions, and grades out really well at all three. Maybe better other places than shortstop, but he can be a really good shortstop.”

Now that he’s with the Athletics, Semien is happy he’s seen as a shortstop first and foremost.

“I think the White Sox believed in me at short too, but they had Alexei Ramirez,” Semien said. “I was happy that they worked with me at those other positions, but now, here? Every rep that I get at shortstop, that’s what I’ve always wanted.”

Semien has already earned rave reviews from manager Bob Melvin for his work at shortstop, especially his range to his left.

There was one question from scouts and inside front offices being asked about Semien’s defense: He had the range, he had the arm strength, but did he have the accuracy on his throws?

Melvin was characteristically frank about the issue, and about the solution.

“Mike Gallego has been working with him, really since the first day of camp here, is to find a consistent arm slot and how to get it there," Melvin said. "We’re aware of that, [but] he has arm strength, and maybe in the past that has been one of his weaknesses. What I’m seeing, it looks like he has a much more consistent spot. I think playing the same position helps too; when you’re playing third it’s a different throw, when you’re playing second it’s a considerably different throw. For a guy that’s as versatile as he is, being young, it’s tough to a lot of times find that consistent arm slot.”

“It was a nice luxury to know that if we needed to move him around, he could, but we’ve never had any hesitation about planting him at shortstop and saying ‘OK, you’re the guy there,” Forst adds. “We’ve seen guys with lesser arms play shortstop in the big leagues. The fact is, he’s a great athlete, he’s going to get to everything that’s hit his way, and I think the arm is strong enough that he’s going to figure it out.”

Veteran Ben Zobrist, no stranger to short since it was the superutilityman’s original position, has liked what he’s seen from his new double play partner, quickly comparing him to one of his former teammates.

“Marcus is a great athlete up the middle, and fundamentally sound,” Zobrist said. “I played with Jason Bartlett, who was very similar: Very rangy, smooth kind of shortstop. Those kind of guys, it’s nice to play with a guy that’s really smooth like that. They’re not going to trick you, they’re just out there making it look super easy. It’s no surprise to me that he has that kind of range, and the ability to not just make every regular play, but extended plays too.”

Working with Zobrist is something that Semien thinks is something he’s getting a real feel for, especially on the double play.

“It’s just about seeing his speed, how he works, how he feeds the ball and knowing where he wants the ball on double plays,” Semien said. “Any time you see something, he gives me input on it, like something with my throws, or going to attack a ball a certain way, he’s pretty good. I’ll always be listening to anything he says.”

That could be an especially key area for improvement for the A's in 2015. Both members of last year's primary double-play combo of Lowrie and Eric Sogard ranked next-to-last in runs saved at short and second, respectively, in Baseball Info Solutions' three-year performance on the double play.

Semien is also looking forward to the challenge of calling the Coliseum his home field, because a rangy shortstop can make a big difference running down balls in its huge foul territory.

“Once we get to Oakland and adjust to that field, all that foul territory affects how the infield plays,” Semien said. “That’s something that can help our pitchers, when they can make a pitch and the hitter flares a pitch and we can clean that up and get it for him.”

Christina Kahrl writes about MLB for ESPN.com. You can follow her on Twitter.