Sometimes they are retread veterans hoping to extend a career, like Erickson and Lima and Alvarez the past three years and Aaron Sele today. Sometimes they are raw prospects stepping up to show they have matured faster than expected, as Howe did in 1981 and Dreifort and Park did in 1994.
The Dodgers opened camp this spring with nine non-roster pitchers in camp. They range in age from 21-year-old Chad Billingsley, the top prospect in the farm system, to 36-year-old Takashi Saito, imported from Japan.
Wunsch probably has the best chance of making the club out of camp. After all, he's already done it.
Rarely a year goes by when there isn't a surprise that rises from these ranks. Last year, when injuries opened up plenty of opportunities, nine of the 19 non-roster invitees appeared for the Dodgers at some point during the season.
The following are capsule rundowns on the non-roster pitchers invited to camp:
Kurt Ainsworth, 27, RHP: Member of the Ned Colletti Connection, a former first-round pick by the Giants who missed the entire 2005 season with Baltimore after surgery to shave down his shoulder blade. A sleeper if he's healthy.
Joe Beimel, 28, LHP: Member of the Roy Smith Connection, having begun his career in Pittsburgh, where he played three full Major League seasons, but he's spent most of the last two in the Minors. In the mix for the situational job. He's a sinker, slider, changeup, ground-ball pitcher
Chad Billingsley, 21, RHP: The top pitching prospect in the organization and top prospect, period, according to Baseball America. He's built like Roger Clemens, idolized Nolan Ryan and made Edwin Jackson expendable. He's supposed to open the season at Triple-A, but seeing him in Los Angeles this year would be no surprise.
Justin Orenduff, 22, RHP: He's been in Billingsley's shadow, but the numbers last year were eye-catching: 94 hits allowed in 126 2/3 innings with 146 strikeouts and 50 walks, splitting time between Class A and Double-A. He was a compensation draft pick from the Yankees for Paul Quantrill.
Takashi Saito, 36, RHP: In Japan, he's been a starter, closer and long reliever. He's probably best considered as insurance if the big-league club runs out of arms.
Aaron Sele, 35, RHP: The most accomplished of the non-roster pitchers with 12 seasons and 137 Major League wins, more than anyone in camp. He was released by Seattle during last season. He'd probably have to beat out Jae Seo for the fifth starter spot. If he doesn't make the Major League club, he can be a free agent.
Eric Stults, 26, LHP: Pitched well last year at Double-A, was pounded at Triple-A Las Vegas. He's come a long way since Tommy John surgery in 2003. A pet project of pitching coach Rick Honeycutt. A changeup, breaking ball pitcher.
Brian Meadows, 30, RHP: The kind of pitcher who can sneak onto a roster. He has six years and 122 starts in the big leagues, but he's taken to the bullpen the past two seasons and the Dodgers are looking for long relievers. He spent four years in Pittsburgh, so he's got VP Roy Smith on his side.
Kelly Wunsch, 33, LHP: So far, appears healed from ankle and hip operations. Funky, sidearm delivery and the most seasoned candidate for the situational left-hander role that is so important in a division with Barry Bonds.