Simon allowed his first runs this season in a four-run ninth inning, with Austin Kearns' three run-blast the decisive blow in Baltimore's 8-2 loss to the Indians Saturday night in front of a crowd of 29,545 at Camden Yards.
"He's pitched very well," Matusz said of Simon, who entered Saturday 5-for-5 in save opportunities. "Some days you just don't have your best stuff. It happens with all of us."
The Orioles' de facto closer in the wake of injuries to closer Mike Gonzalez and setup man Jim Johnson, Simon had tossed eight scoreless outings since his contract was purchased on April 27. Only a year removed from Tommy John surgery on his right elbow, Simon has made a living this season out of high-wire save opportunities. But he couldn't wiggle his way out of this one, surrendering a two-run lead and exiting in favor of sidearmer Cla Meredith after allowing four runs on three hits and a walk.
"I [want to] say, 'Sorry' to [Matusz] because he worked hard to win the game," Simon said.
"Sometimes, in a situation like that, you make a mistake and you learn from that."
Trembley wouldn't say one way or the other whether Simon's pitch -- a belt-high splitter -- was the right decision. But the O's manager didn't second-guess his decision to leave Simon in the game.
"For me right there, he's the best guy for that situation, facing Kearns," Trembley said. "He got himself in trouble, you get yourself out of it. I think you go power against power. It's worked. He made a bad pitch."
The Indians' first run came via a one-out RBI single from Shin-Soo Choo, who scored Asdrubal Cabrera. Simon recorded the first out of the inning before Cabrera singled and Mark Grudzielanek walked. Following Kearns' homer, Simon was replaced by Meredith, who was charged with another quartet of runs -- including a two-run homer to Trevor Crowe -- to put the Indians up six runs heading in to the bottom of the ninth.
"I got to come out with a little more aggression right there," said Meredith, who issued a full-count walk to the first batter he faced and was tagged with his first earned runs in 12 appearances.
"The inning hadn't gone like we planned. I tried to come in and make sure the damage doesn't get any worse and I came out a little flat and things snowballed on me a little bit."
Meredith couldn't stop the scoring, but it was Simon's blown save that tarnished another impressive evening Matusz, who seemed poised to snap a professional-high three game losing skid.
Matusz spent the first seven innings locked in a pitching duel with fellow rookie Mitch Talbot and rebounded from his worst start of the season to put the Orioles in line for a win.
"[Matusz is] going to give you what he's got all the time," Trembley said. "What he does have is a very good knack for coming up with the big pitch when he has to. He doesn't give in. He does not give in, which is commendable."
Just 23, Matusz pitched around a baserunner in each of the first six innings, helping the Indians strand seven men on base through the game's first two-thirds. He ran into his biggest jam of the day to start the seventh, issuing a pair of walks to Cleveland's bottom two batters. Cabrera's sacrifice bunt put the tying and go-ahead runs in scoring position, but that was as close as Matusz would let the Tribe get. He retired Mark Grudzielanek on a shallow fly to right, with Nick Markakis' pinpoint throw to the plate forcing the Indians runners to stay put. Matusz proceeded to get Choo on an infield groundout, denying the Tribe's best clutch hitter a chance to seize the momentum. Instead, the Indians went 0-for-4 with runners in scoring position when Matusz was on the hill.
"He threw well for his age; he shows a lot of poise out there," Indians manager Manny Acta said.
"He changed his pattern on our guys a lot. Started early in the game establishing his fastball, then he went to his change-up, and then third time around, he was dropping that good breaking ball on them. I'm glad he was out of there [in the eighth], and things worked out for us."
Matusz allowed seven hits -- all singles -- over seven shutout innings, walking four and striking out six. Saturday's start was his first scoreless outing of the year and his longest outing since lasting 7 1/3 innings in April 13's no-decision.
Talbot was nearly as impressive, going eight innings and being tagged for two runs, both off the bat of Ty Wigginton.
Wigginton went yard for a one-out solo blast off Talbot in the second inning, crushing a 78 mph changeup an estimated 414 feet over the left-field fence. Talbot responded by retiring the next seven straight and didn't allow another run until Wigginton's second homer, a 362-footer that barely eclipsed the wall. Playing in place of injured second baseman Brian Roberts, Wigginton has hit 12 homers this season, already more than the 11 long balls he had all of last year.
Talbot outlasted Matusz -- tossing eight innings of two-run baseball -- and picked up his fifth win in the process. Despite the loss, the Orioles still have a chance to take the series in Sunday's rubber match.
Brittany Ghiroli is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.