There have been six players who saw action in only one game for the Padres. All of them spent time with other teams, so they aren't true cup-of-coffee players in the strictest sense of the term. However, most of them didn't do much in their other stops either, so it's just as well they didn't get into a second game with the Friars; at least this way they're getting remembered for something.
Al McBean was the first of the half-dozen, way back in 1969. He started, and took the loss in, the fifth game in franchise history, giving up four earned runs on ten hits and two walks spread over seven innings. McBean had the longest career of the bunch by far, spending eight successful years with Pittsburgh before being selected with the fiftieth pick in the expansion draft. After his single game with San Diego, McBean was sent to the Dodgers for Leon Everitt and Tommy Dean. Used strictly as a reliever by Los Angeles, he got into 31 games the rest of the season and then, strangely enough, just one in 1970 before being released. He hooked back up with the Pirates and got knocked around for seven games before he was cut loose one last time.
It would be nearly 27 years until another player would join the one-game club. Outfielder Todd Steverson, whom you might recall being hired as the White Sox's new hitting coach a couple weeks ago, made his sole appearance for the Padres in April, 1996, after getting into 30 games with the Tigers the year before. Bruce Bochy sent him to the plate in Joey Hamilton's spot and Steverson struck out looking. It was to AAA Las Vegas after that and he never returned to the majors.
The Padres wouldn't have to wait nearly as long for the next one-timer. Pete Walker got his shot that September 7. Like Steverson, Walker appeared in a handful of games the previous season with a different team that wore blue and orange; in his case it was the Mets. Also like Steverson, he had a rough go of it in his one game with the Padres. It was going well at first; he retired the first two batters he faced after being summoned to pitch the eighth inning of a game the Cardinals were winning 8-3. Walker then proceeded to live up to his name by issuing free passes to Luis Alicea and a pair of players who were also once Padres, Mark Sweeney and Ozzie Smith. Having seen enough, Bochy brought in Mike Oquist, who retired future Friar Ray Lankford and saved Walker from having any earned runs attached to his name. It would take Pete until the year 2000 to make his way back to the bigs; he got into three games with the Rockies that season and two more with the Mets in 2001 before finding a solid role with Toronto for four seasons.
The fourth Friar to play just one game for the team was left fielder Jermaine Clark in 2003. Clark's case was an unusual one in that he played in 10 games with the Rangers that season before his sole game with the Padres, and 14 more games with the Rangers after it. He was waived by Texas and picked up by San Diego in late April, and then sold back in early July. His one game between the two deals was a 3-2 loss to Milwaukee in which he went 0-2 with a sacrifice fly for the only RBI recorded by any of the one-game wonders. In addition to his 25 games in 2003, Clark got into three games solely as a pinch-runner with the 2001 Tigers, 14 games with the Reds in 2004, and put a bow on his career with four games and no at-bats for the 2005 A's.
A little more than three years after Clark's day at Qualcomm, Justin Leone put his name in the Padres' record book. The big third baseman was sent to the plate in place of Doug Brocail with two outs in the eighth inning of a game in San Francisco, tasked with facing Matt Cain. He flied out to right fielder Moises Alou and that was that. Leone, who hit six homers in 102 at-bats with Seattle in 2004, wound up with a final major league total of six homers in 103 at-bats.
The most recent member to join this strange club was right-handed reliever Aaron Rakers. He put up great numbers in 13 games with Baltimore in 2004 and '05, but missed all of '06 due to shoulder surgery and came to the Padres as a free agent before the '07 season. Wearing the number 57 last worn by Jon Adkins, Rakers pitched the ninth inning of an 11-6 victory over Arizona to preserve the third win of Jake Peavy's Cy Young season. Aaron allowed only one hit in his full inning of work, a single to Chad Tracy. The three batters he retired would all go on to become Padres themselves - Orlando Hudson, Scott Hairston, and Carlos Quentin. Despite his fine work, Rakers was sent back to AAA Portland and scuffled the rest of the season. 2008 saw him try his hand at starting in the independent Atlantic League, and from there he moved on to Taiwan. He was voted the best pitcher in the league there in 2009, but he regressed the next season and hung 'em up after his release.
I hope you enjoyed reading this as much as I enjoyed researching and writing it. Baseball's full of stories I could never dream up; I hope I never lose my passion to go digging for them.