Prior to delivering seven innings of one-hit ball against Pittsburgh on Wednesday -- his first win since May 2 -- Arrieta had given up 23 earned runs over his previous four starts. Entering Monday's series opener against the Mets, his ERA is 5.89, but he insists he has gotten back on track.
"Now I'm kind of back to the frame of mind I was in last year and where I was earlier this year," Arrieta said. "I'm extremely relaxed. I've always been confident, even when I struggled, but it's more of a confidence with a calmness. I've done my work on and off the field. I've watched video."
Tommy Hunter will start for Baltimore in the second game of the series, followed by Brian Matusz in the finale.
Getting the nod on Monday for the Mets is R.A. Dickey, who, with a 10-1 record and 2.20 ERA, is one of the hottest pitchers in baseball.
In his most recent start -- a one-hit, complete-game effort against Tampa Bay -- Dickey saw his career-best 32 2/3-inning shutout streak come to a close after surrendering an unearned run in the ninth. He has turned in quality starts in 10 consecutive outings.
Johan Santana will start on Tuesday, still looking to get back on track after tossing the franchise's first no-hitter on June 1. In his two starts since, he has allowed 10 earned runs in as many innings.
Dillon Gee will take the mound in Wednesday's finale.
Mets: On a sweep streak
The Mets' last three series have ended in a sweep, but only one went in their favor.
After being swept by the Yankees last weekend, the Mets took all three games from the Rays at Tropicana Field before being swept by the Reds at home.
What was the difference? Offense.
The Mets scored seven runs total in three games against the Yankees and just five in the three-game set against the Reds. But their offense clicked against the Rays, as they scored 29 against a dominant Tampa Bay rotation.
"We're sputtering a little bit offensively," third baseman David Wright said. "Our starting pitching hasn't been bad, but we just haven't been able to get them any runs."
Orioles: Birds are flying high
The Orioles have been on a tear, winning eight of their last nine games.
Baltimore has scored 47 runs during that stretch, including a 12-run outburst against the Pirates on Thursday.
Even more impressive, they are scoring without the services of Nick Markakis, who was hitting .256 with eight home runs before undergoing surgery on his right wrist.
Baltimore has a 9-3 record in Interleague Play this season, trailing only the Yankees (10-2).
The Mets swept the Orioles in the teams' last meeting, a three-game set in June 2010.