Rothschild said Wood did a full long-toss program before he took the mound, which not only gets him warmed up but also helps increase his arm strength.
"As we do more throwing, it takes a little longer to get loose because we're trying to tire his arm out to build it up, and he hasn't been having any problems," Rothschild said. "He loosens up fine after about 30 [throws]. That may be a routine he's got to keep."
Wood focused on throwing fastballs on Friday, although he did mix in a few curves.
"He threw some breaking balls today -- we're really concentrating more on building arm strength," Rothschild said. "We'll spin the ball some, but I don't really worry about the breaking ball as much as some other pitches until the arm strength gets built up. Those things will come back."
Wood's next step will be another batting practice session in Mesa, Ariz., where he'll continue his rehab while the rest of the team heads north to start the regular season.
Prior update: Fellow right-hander Mark Prior also is coming back from arm trouble and will begin the season on the disabled list. After resting for nearly two weeks, he threw on flat ground on Thursday for Rothschild and on Friday for trainer Mike O'Neal.
"It's been good to see where he is," Rothschild said of the two sessions. "Even with the 13 days off, he didn't lose a whole lot, and he might have actually gained some. ... The ball is coming out with some force. We can progress him as his daily work allows."
Walker's the man, for now: Manager Dusty Baker revealed on Friday that Todd Walker would start at least the first two games of the season at second base. And although he said Walker is his "primary" second baseman, Baker insisted he'd determine his lineup based more on situational need than just right-left matchups.
"Everybody plays on my team, and there's a spot and time for all of them," Baker said. "It's not a platoon; it's a situation where [I'll play] who I think is better-suited that day to help us win -- whether we need offense, whether we need speed or infield defense."
Walker gets the early nod because the Cubs open the season against Cincinnati's Aaron Harang and Bronson Arroyo, two right-handers who are notoriously tough on right-handed hitters. That leaves Jerry Hairston on the bench, with Neifi Perez and even newly acquired Freddie Bynum still in the mix.
When asked if Hairston was OK with the news, Baker said, "He seemed to be. Like I told him, I didn't expect him to be happy about it. I just expect him to respect it and to accept it."
No dice for Baker: Cubs fans in Las Vegas hoping to catch a glimpse of Baker on the city's famous Strip this weekend will be disappointed. Baker said he's not much of a gambler, dating back to a childhood incident that made a big impression on him.
"My dad broke my dice as a kid," Baker recalled on Friday. "My sister snitched on me, told my dad I had some dice, so he took them out on the driveway and busted them with a hammer.
"Broke my heart," he added with a hearty laugh. "I was going to get rich in elementary school."
Quotable: "I think I'll be able to appreciate it more than if I were in, say, my first or second year. I do appreciate it. I grew up here. I've loved living here and I continue to like living here, and it's kind of an honor to get a chance to pitch here." -- Las Vegas native Greg Maddux, on starting Saturday's game in his hometown
Cubs crumbs: The Cubs will work out on Sunday at 2 p.m. CT at Great American Ball Park in Cincinnati to prepare for Monday's season opener. ... The Cubs are 7-0 this spring when they've hit two or more home runs in a game.
Up next: The Cubs will play the Padres in the second of two exhibition games in Las Vegas at 2:05 p.m. CT on Saturday.