SCOTTSDALE, Ariz. -- The first session of live batting practice drew a crowd, but for the Giants hitters involved, there wasn't all that much buzz.

With Farhan Zaidi, Scott Harris, Gabe Kapler and half the coaching staff watching from behind the backstop, and the analytics staff set up to track pitch characteristics and swings, Brandon Belt stepped up to the plate and took a couple of walks. Buster Posey did the same, tracking pitches into the catcher's glove and then retreating to the dugout to tell hitting coach Donnie Ecker what he was seeing.

And then Pablo Sandoval dug into the batter's box.

Sandoval swung at the first five pitches he saw from prospect Luis Madero, fouling a couple off and lining a couple into the grass. He was just as aggressive in his second session. When Kapler sat down with reporters a few minutes later, he was still laughing over Sandoval's mentality.

"I've never seen an approach to live BP like Pablo just took," Kapler said.

The manager loved seeing it for a couple of reasons. First of all, Sandoval figures to be Kapler's top pinch-hit option for most of the year, in part because of that aggression. Kapler said earlier this week that he always feared seeing Sandoval step in when he was managing the Phillies, in large part because he knew Sandoval would be ready to do damage from the first pitch, unlike many hitters who like to first look at a couple offerings in the late innings.

"It kind of demonstrates why he's so dangerous at the plate, because he's just prepared to drive every pitch," Kapler said. "Generally you calibrate one of two ways: By taking and seeing pitches, and the second way is by swinging at pitches -- and he just took aggressive hacks on everything that was thrown up there."

The second reason Kapler liked what he saw was health-related. Sandoval is well ahead of schedule in his rehab from Tommy John surgery, but he's still likely to miss the first month of the season as he works his throwing arm back into shape. The Giants have, though, discussed the fact that at some point they may have a tough decision to make.

With a 26th roster spot, they could, in theory, carry Sandoval as he continues to rehab, using him only as a pinch-hitter. On Tuesday, as Sandoval hungrily went after two-seamers and changeups from Madero, he looked the part of someone who could be ready for a hitting-focused role on Opening Day. Kapler noted that Sandoval was "right on" every pitch.

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"He's been thinking about his swing for a long time and working on his swing for a while now," Kapler said. "It's going to be like a bit of a tricky puzzle, because we're going to want to get him reps at his pace earlier in camp, and at the same time we know that he's not going to be ready at the same pace as some of our other players.

"We want to be respectful of the pace that he wants to work at, so we're going to have to weigh those two factors."