PHOENIX -- With Justin Upton getting closer to a return from the disabled list, third baseman Mark Reynolds took grounders at second during batting practice Wednesday.

It was the first time this year that Reynolds has done that and could be a sign that the D-backs are seriously considering a scenario that would involve shifting Reynolds to second.

"If they want me to I will," Reynolds has previously said of playing second. "It won't affect anything. I feel comfortable over there, I feel comfortable at third base. Whatever they want."

The season-ending injury to second baseman Orlando Hudson opened a hole in the infield. Combined with the acquisition of outfielder Adam Dunn and the expected return of Upton, it suddenly becomes a challenge for manager Bob Melvin to keep everyone in the lineup.

One scenario has Dunn moving from right to first, Chad Tracy from first to third and Reynolds from third to second.

That could significantly weaken the team defensively, given that Tracy has played third just twice this year and is coming off major surgery on his knee and that Reynolds has not played second base regularly since spending some time there last year with Double-A Mobile.

Reynolds practiced flipping the ball to second for double plays as well as working on his pivot at the bag.