Both are right-handers, but Duchscherer does not possess the wicked speed Harden fires out every five days. Nor does Duchscherer have five-plus years of experience as a Major League starter, as does his newly departed former teammate.
But on the same day the A's shipped off Harden and pitcher Chad Gaudin to the Chicago Cubs in a six-player deal, Duchscherer assured the Oakland contingent that an ace still resides in the clubhouse.
Just two days after being named to the American League All-Star squad, Duchscherer fittingly tossed a performance resembling the stuff deemed worthy of a Midsummer Classic trip. The righty threw his first career shutout on Tuesday as the A's grabbed a 2-0 victory against Seattle in the second of a four-game set at McAfee Coliseum.
"I didn't expect to go out there and throw like that," Duchscherer admitted. "I've gone out and felt better in my bullpens, but I just got in the zone.
"I can't give enough credit to [Kurt] Suzuki and the job he did. We got locked in."
Locked in may be somewhat of an understatement. Duchscherer, in his first full season as a starter after having spent the better part of four seasons as a reliever, looked like a seasoned ace on the mound while finishing Oakland's quickest game this season in 1 hour, 49 minutes.
"That was pretty quick," said a pleased manager Bob Geren. "I looked up at one point and it was already the fourth inning. I can't say enough about Duchscherer -- everything about him is efficient."
Efficient is tossing four innings of no-hit ball before giving up the first Mariners hit of the night -- a double off the bat of Richie Sexson -- with two outs in the fifth inning. Efficient is allowing just one more hit the rest of the game while throwing 105 pitches. When the no-no started garnering whispers among the 12,543 fans in attendance, though, Duchscherer had other things on his mind.
"At that point in the game I'm just worried about getting outs," he said. "I wasn't disappointed about the hit; I was disappointed because I made a bad pitch."
He'll take one bad pitch, though, if it means 104 good ones to keep opposing runners out of sight.
"I've always felt more confident with the bases cleared," he said. "Anytime you can limit baserunners, it helps."
It's safe to say he did his job, as he faced just three batters over the minimum without walking anyone. The last time an A's pitcher threw a complete game two-hitter was on July 14, 2005, coming from the arm of none other than Harden.
"He changed speeds and threw strikes," said the Mariners' Willie Bloomquist, who went 0-for-4. "He mixed pitches and was hitting his spots. ... That's what pitching is all about, I guess."
As Seattle manager Jim Riggleman noted, though, Duchscherer wasn't the only one leaving hitters frozen. On the other side, Mariners starter Carlos Silva limited the A's to two runs on seven hits through eight innings, striking out five.
"Both [pitchers] were equally outstanding," Riggleman said. "The first couple of innings, Carlos wasn't as sharp as he became later on in the game, but their guy displayed why he's an All-Star."
The A's relied on some timely hitting to provide their ace with just enough offensive support for their second straight victory. Emil Brown knocked an RBI single in the first inning to bring home Ryan Sweeney, who led off the frame with a single, to put Oakland ahead, 1-0.
In the second inning, the A's added to their lead when Suzuki and Jack Hannahan hit back-to-back singles and Donnie Murphy followed with a sacrifice fly to center field to put Oakland in front, 2-0.
"All in all," Duchscherer said, "a great team win."
While dominant pitching and small ball wrote the script for Tuesday's affair, Oakland's relief staff got a much-needed night off in the wake of a grueling non-stop schedule.
"We're in the middle of 20 straight games," Geren said, "so it's always nice to give the bullpen a break."
No rest needed in the game for Duchscherer, though. By sealing his 10th victory of the year, he became the fifth Oakland pitcher since 1993 to earn 10 wins before the All-Star break. On top of that, he lowered his Major League-leading ERA to 1.78.
"After seven innings, I asked him how he was doing," Geren said. "He said, 'OK' and I asked, 'Just OK?' But then he said, 'No, I feel good.'
"And I didn't bother him again."
Jane Lee is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.