Vogelsong is a 35-year-old veteran who scuffled his way through an undistinguished career with the Giants and Pirates before taking advantage of an opportunity to seize a spot in the starting rotation last year.
Richard has stayed strong as the Padres have struggled through the 2012 season, never missing a start and pitching the most innings in the National League before Sunday's games.
Vogelsong is 7-4 with a 2.31 ERA. He's had 14 quality starts and has pitched at least six innings in each of his 17 starts.
Out of the Majors since 2006, Vogelsong signed a Minor League contract with the Giants prior to last season and joined the big league club when Barry Zito was injured.
He made two relief appearances and then became a starter for the first time since 2004 and ended up making the All-Star team.
For the season, Vogelsong went 13-7 with a 2.71 ERA in 30 total appearances.
The Giants have won 11 of his last 13 starts and are 12-5 overall in his outings this season.
Probably because he has struggled and it took so long to finally establish himself as a Major League starting pitcher, Vogelsong acknowledges he pitches with a bit of an attitude.
"People don't take me seriously," Vogelsong said in a recent interview. "I've been pitching with a chip on my shoulder since I got here last year. I've still got something to prove. I'll probably pitch with that chip the rest of my career."
Vogelsong has recovered after being sidelined with back problems for much of the spring and spending a short rehab stint at Triple-A Fresno.
"There were times in the spring where I didn't know how it would be," Vogelsong said of his back. "But I don't think about it. Really, after the first two starts, I got that out of the way. I had a couple of starts under my belt and realized that I'd be OK. That was pretty much the end of it."
Richard has been brilliant lately for the Padres, despite the four runs he allowed in his last start.
The 28-year-old left-hander worked 8 1/3 innings in an 8-4 victory over the Astros, allowing nine hits and four runs to lift his record to 7-10. He has a 3.86 ERA in his 20 starts.
The four runs came from two swings from one guy hitting under .200 overall as Matt Downs hit a solo and three-run homer.
He hasn't been striking out a lot of batters, instead pitching to contact.
"I don't think you ever make a pitch hoping someone's going to hit it," Richard said Sunday. "I think it's more working aggressively toward the glove, down in the zone.
"You want to make pitches to where if they do hit it, it's a mis-hit."
Padres: Quentin gets contract extension
Outfielder Carlos Quentin has reached an agreement with the Padres on a $27 million, three-year contract extension, the team announced Sunday.
Giants: Cabrera hitting .356
All-Star Game MVP Melky Cabrera is hitting .356 with 10 home runs and 49 RBIs. He had a double in four at-bats in Sunday's 4-3, 12-inning loss to the Phillies.
Monday's game is the beginning of an 11-day, 10-game homestead for the Giants after they went 4-2 on a road trip to to Atlanta (2-1) and Philadelphia (2-1).