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04/28/2013 4:18 PM ET

Ross set to start Minor League rehab assignment

SAN DIEGO -- Pitcher Tyson Ross, who has been on the disabled list since April 20 with an impingement in his left shoulder, will begin a Minor League rehabilitation stint this week with Triple-A Tucson.

Ross, who is expected to pitch Tuesday in Tacoma, landed on the disabled list after partially dislocating his left (non-throwing) shoulder taking a swing while hitting against Dodgers pitcher Clayton Kershaw on April 17 at Dodger Stadium.

That swing actually resulted in his first Major League hit. Ross remained in the game and came within one out of qualifying for his first victory of the season. Overall, Ross is 0-1 with a 3.86 ERA in three starts.

While on the disabled list, Ross has been replaced in the rotation by Andrew Cashner, who allowed one run in six innings Friday against the Giants and figures to remain in the rotation. If Ross is to return to the starting rotation, then someone likely will have to be bumped from it.

Ross shouldn't need much time on his rehabilitation stint as he's has been able to keep his right arm in shape during his time on the disabled list. The team wanted to make sure the left shoulder held up well to hitting and also fielding his position before they sent him out on a rehab assignment.

Third-base coach Hoffman making great reads

SAN DIEGO -- Third-base coach Glenn Hoffman can go weeks -- or even longer -- without facing a difficult decision on whether to hold a runner.

He's faced two in the last two games and both ended up being wise decisions.

On Saturday, Hoffman held Yonder Alonso at third base after a sharp single to right field by Jedd Gyorko in the 12th inning. Alonso was on second base but Hoffman held him for several reasons. One was that Alonso doesn't have the swiftest speed; the other was the arm of Giants right fielder Hunter Pence.

"When Pence goes to his left and with the way he throws, he's pretty accurate," Hoffman said. "If you have [Will Venable] running, then he's closer to me."

Alonso eventually scored the winning run in the Padres' 8-7 victory in 12 innings after Giants second baseman Marco Scutaro was charged with an error on Nick Hundley's ground ball with one out.

On Friday, Hoffman held pitcher Andrew Cashner at third base on a Chase Headley single with two outs. Carlos Quentin then delivered an RBI single and Alonso did the same in a game that the Padres won, 2-1.

"It looks good when you get them in," Hoffman said. "It worked out."

That's in large part, manager Bud Black said, because of Hoffman's experience and his ability, more often than not, to make the right call quickly.

"It's a job that really goes under the radar, and Glenn is one of the best in baseball," Black said. "These guys study their craft, they know how to track outfielders, their arm strength. Hoffy makes, very, very few mistakes.

"It's a role on the team that doesn't get a lot of credit. If things go bad, a third-base coach can take some ridicule."

Erlin's time coming, says Padres skipper

SAN DIEGO -- It's been four days since the Padres recalled left-handed pitcher Robbie Erlin from Triple-A Tucson but entering Sunday, his biggest contribution has been to carry the team's gum and candy to the bullpen before each game.

On Sunday, Padres manager Bud Black was asked when Erlin would pitch.

"I'm a Robbie Erlin fan, from what I've seen," Black said. "His time is coming soon."

Erlin was promoted Wednesday, the day the team sent pitcher Thad Weber back to Tucson. Weber had provided the Padres 4 2/3 scoreless innings the previous day against the Brewers and the team needed another long reliever to join Anthony Bass in the bullpen.

The Padres began the season with Bass and Cashner as the long relievers but Cashner has since joined the starting rotation.

In Saturday's 8-7 victory over the Giants in 12 innings, Black used six relievers to cover eight innings. The only reliever who wasn't used was Erlin, though that was by design.

The Padres needed to hold back Erlin in case Sunday starter Jason Marquis departed early and the team needed an arm out of the bullpen capable of working multiple innings.

Short hops

• Pity poor outfielder Chris Denorfia, but not because of anything that's happened to him on the field. In fact, he's hit safely in 17 of his last 20 games and had a big two-run double in Saturday's 8-7 win over the Giants. Denorfia was hit atop his head before Saturday's game while stretching after teammate Everth Cabrera lost his grip on the bat. Then during the game, Cabrera lost his bat on the swing and it went pinwheeling into the dugout. The bat actually hit Denorfia in the back as he tried to elude it.

• Tommy Medica, a first baseman for Double-A San Antonio, was placed on the disabled list Sunday with a lat strain. Medica was hitting .306 with six home runs and 15 RBIs when he suffered the injury. To replace him, the team moved infielder Cody Decker from Triple-A Tucson to San Antonio.

Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.