Extra bases

• Cubs pitcher Jake Arrieta, slowed by tightness in his right shoulder, threw off flat ground from about 90 feet on Saturday.

The key will be how Arrieta feels Sunday, Renteria said, before they determine the next step. So far, Arrieta is making progress, but whether he'll be ready by Opening Day has not been determined. He has yet to throw off a mound.

• Renteria, 52, threw batting practice Saturday and plans to continue to do so as long as the players let him. The problem, besides a few aches and pains, is location.

"I just have to throw strikes," Renteria said, sounding like a pitcher.

He can tell if he's doing well because there aren't many balls in the cage after the batting practice session.

"I had a lot of balls back there," Renteria said. "Usually I have one or two, and today I had 10 or 11. That's not good."

• The Cubs have more than 50 Minor League players taking part in a mini-camp at the team's new complex. One player who fans most likely won't recognize is Daniel Vogelbach, who lost 30 pounds this offseason. Vogelbach is the Cubs' 10th-ranked prospect, according to MLB.com.

• The best investment by Cubs players this spring? Goggles for the new hydrotherapy pool in the complex. Carlos Villanueva, who likes to incorporate swimming into his routine, spent $20 on a pair, and is encouraging others to do so.

Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.