SCOTTSDALE, Ariz. -- In one of general manager Brian Sabean's more successful trades, the Giants sent right-hander Ryan Vogelsong and outfielder Armando Rios to Pittsburgh for right-hander Jason Schmidt and outfielder John Vander Wal on July 30, 2001. Schmidt became an ace, making the swap a bonanza for San Francisco.

That deal didn't necessarily end Vogelsong's future with the Giants. It might have been merely interrupted.

For now, Vogelsong's back with the organization as a non-roster invitee to camp. Though he's a long shot to make San Francisco's season-opening pitching staff, he potentially can provide depth with his ability to start or relieve.

"I've been trying to get back here since I got traded. I loved it here so much," Vogelsong said Sunday, citing his relationships with pitching coach Dave Righetti, bullpen coach Mark Gardner and vice president of baseball operations Bobby Evans, among others in the organization. "It feels good to be back in familiar territory with familiar people."

Much has changed since Vogelsong, a fifth-round selection in the 1998 First-Year Player Draft, last inhabited the Giants' clubhouse at Scottsdale Stadium.

The year was 2001. Vogelsong was a 23-year-old prospect, having led the Texas League and all Giants farmhands the previous year with 147 strikeouts. Barry Bonds dressed in an adjacent stall.

Then came the trade. Vogelsong, who had brief relief stints with the Giants in 2000 and 2001, endured Tommy John elbow surgery in 2002 and went 10-19 with a 6.00 ERA for the Pirates from 2001-06.

Vogelsong pitched in Japan from 2007-09 before returning to the U.S. and performing in Triple-A for the Phillies and Angels last year. He proceeded to excel for Tiburones de La Guaira in the Venezuelan Winter League, finishing 6-2 with a 2.25 ERA in 11 starts. Teammate Guillermo Rodriguez, a former Giants catcher, recommended Vogelsong to Evans, which led to the reunion.

Vogelsong received a competing offer from the Dodgers. But his decision came easily.

"I was like, I just can't wear Dodger blue," he said.

Wilson improving, getting in work

SCOTTSDALE, Ariz. -- Despite lingering back stiffness, Brian Wilson has continued to keep his arm limber and is "making more progress," manager Bruce Bochy said Sunday.

Bochy said that Wilson played catch Sunday, one day after throwing off a bullpen mound. Bochy believed that Wilson will be able to handle another bullpen session Monday.

The weekend's cold, wet weather prompted the Giants to excuse Wilson from participating in on-field drills. Rain prevented the Giants from staging those drills Sunday, anyway. An unconcerned Bochy noted that the Giants will have plenty of opportunities to review fundamentals.

"We'll make it up tomorrow," he said.

Romo not taking roster spot for granted

SCOTTSDALE, Ariz. -- Based on numerous facts and figures, the conclusion that Sergio Romo entrenched himself in the Giants' bullpen last year was inescapable to everyone.

Everyone except Romo himself, that is.

Romo's career-high 68 appearances ranked second among the Giants, yet he won't assume that he has a spot reserved on the Opening Day roster.

"I don't feel that I'm established enough in the big leagues to be comfortable," Romo said.

Romo, who finished 5-3 with a 2.18 ERA in 2010, believes that he can cement his status by improving his changeup, a pitch he has rarely used in recent seasons. The right-hander knows that he must refine the mechanics he employs when he throws it.

"I'll drop the elbow a little bit or push it or slow down my motion," said Romo, 27. "I'm trying to throw it like I throw my sinker."

Romo plans on refining his changeup during Cactus League exhibitions.

"I don't want to be just a right-handed specialist," he said.

Romo's role was much more significant than that last year. He was one of the primary setup men for closer Brian Wilson, appearing in the eighth inning or later in 47 games. Romo's ERA ranked 10th among National League relievers who amassed at least 60 innings. He blanked opponents in 48 of his last 54 appearances, recording a 5-0 mark with a 1.50 ERA in that span.