Here are some quick notes from today’s off-season practice, which the 49ers allowed the media to watch.

-The Randy Moss-Alex Smith chemistry is on. The two connected often in team drills. “He’s just so easy to throw to,” Smith said. He also called Moss “incredibly smart.”

-Tight end Delanie Walker went down in the middle of practice and stayed on the ground for several moments while athletic trainers tended to his left knee. Walker never left the field, however, and watched the rest of practice with an ice bag on the area. He said he’s fine and hopes to practice tomorrow.

-Coach Jim Harbaugh noted that Kyle Williams is still the backup to Ted Ginn Jr as a returner. Williams looked devastatingly quick returning kickoffs on Wednesday. Ginn was at practice but he did not take part. Harbaugh declined to discuss Ginn’s injury.

-Wide receiver Michael Crabtree also looks good and Smith threw him plenty of passes. Smith said Crabtree is running as well as he’s ever seen him. Because of a contract holdout, the lockout and assorted injuries, this is the first significant off-season time Crabtree and Smith have spent together.

-Harbaugh said on KNBR Friday that Michael Crabtree had the best hands he had ever seen and he wasn’t backing down from that comment. “The comment stands on its own merit,” Harbaugh insisted. “I know you guys have dissected it about every which way it could be dissected, but it is literal fact, as I see it, and believe it to be.”

-In one-on-one drills, cornerback Tarell Brown made a nice interception.

-Rookie wide receiver A.J. Jenkins struggled. He had a tough time catching the ball cleanly and he dropped a lateral.

-Second-year player Mike Person looked terrific in a drill testing the ability to handle the stunt. Person could be the team’s swing tackle if Alex Boone succeeds as the starting left guard.

-Speaking of Boone, Harbaugh said he’s been doing a “phenomenal job” at guard. Boone said of his transition from tackle, “I love it, it’s truly a fist fight.”

-Punter Andy Lee said he wouldn’t mind seeing his yards per punt average go DOWN. Lee said it would mean he was dropping more punts inside the 20.

-Many, including myself, have focused on Alex Smith’s lack of 300-yard passing games last year (he didn’t have any). Here’s what he said about it, “This is the honest truth: I could absolutely care less on yards per game. … I think that’s a totally overblown stat. Because if you’re losing games in the second half, guess what? You’re like the Carolina Panthers and you’re going no-huddle the entire second half and, yeah, Cam Newton threw for a lot of 300-yard games, that’s great. You’re not winning, though.” Good point by Smith.

-Harbaugh also said that tackle Anthony Davis’ footwork is much improved.