Manager: Lloyd McClendon, first year Record: 56-52 Last 10 games: 4-6 Who to watch: 2B Robinson Cano (.328/.389/.453, 25 doubles, 7 HR, 59 RBIs); 3B Kyle Seager (.281/.348/.486, 25 doubles, 16 HR, 67 RBIs); RHP Hisashi Iwakuma (9-5, 3.06 ERA, 0.99 WHIP); LHP James Paxton (2-0, 2.25 ERA, 0.67 WHIP) Season series vs. O's: 1-3, 7 runs scored, 12 runs allowed Pitching probables Aug. 1: Roenis Elias vs. Wei-Yin Chen, 7 p.m., MASN2 HD Aug. 2: James Paxton vs. Miguel Gonzalez, 7 p.m., MASN2 HD Aug. 3: Hisashi Iwakuma vs. Chris Tillman, 1:30 p.m., MASN2 HD Series breakdown The Orioles complete a stretch of 16 straight games against American League West foes by facing the Mariners for the second time in three series. Seattle comes to Baltimore having lost six of nine games, a stretch that includes three defeats in four contests against the Orioles at Safeco Field. But the Mariners look a little different after making two additions at Thursday's non-waiver trade deadline, acquiring center fielder Austin Jackson from the Tigers and outfielder Chris Denorfia from the Padres. Jackson is a strong defender who is batting .273/.332/.398 with 25 doubles, five triples, four homers and 33 RBIs. Denorfia is more of a platoon type. Overall, he's hitting .242/.293/.319 this year. But in his career, he's a .301/.367/.443 hitter against left-handers. Now that the new faces have been covered, let's get down to reintroducing the Mariners. Seattle still owns the best pitching staff in the majors, leading the league with a 3.08 team ERA. The Mariners' 2.39 bullpen ERA also is tops the majors while their 3.41 starters' ERA is the second-best mark in the AL. The relief corps is centered around six arms that have posted ERAs of 2.68 or better in at least 37 appearances - closer Fernando Rodney (2.06 ERA, 30 saves), right-handers Dominic Leone (2.27 ERA), Tom Wilhelmsen (2.34 ERA), Yoervis Medina (2.43 ERA) and Danny Farquhar (2.68 ERA), and left-hander Joe Beimel (1.34 ERA). After having to go through the Mariners' top three starters in Seattle, the Orioles get an interesting draw this time around. Rookie left-hander Roenis Elias (8-8, 4.31 ERA) goes up against Wei-Yin Chen in the opener. Six days ago, Elias held the Orioles to one run in five innings for a no-decision. The Mariners lost that game 3-2. Fellow rookie left-hander James Paxton pitches against Miguel Gonzalez on Saturday and is perhaps the most intriguing Seattle starter in the series. Paxton earned a spot in the rotation out of spring training, and had an excellent start to the season. He went 2-0 with a 2.25 ERA while allowing just eight baserunners and striking out 13 in 12 innings over two starts. He then strained his left lat muscle and has been out since April 8. This will be his first start back from the 60-day disabled list. And then the series wraps up with its best match-up, between right-handers Hisashi Iwakuma and Chris Tillman. Iwakuma remains the Mariners' second ace, having gone 9-5 with a 3.06 ERA, which ranks 11th in the AL, and a 0.99 WHIP, which ranks third. He had some minor trouble with the Orioles in Seattle, however, snapping a streak of four straight quality starts by allowing four runs in seven innings for his first loss since June 25. While the Mariners have all that pitching, their offense has left something to be desired, which is why the additions of Jackson and Denorfia could be a factor going forward. Seattle ranks 15th in the AL with a .670 OPS, 14th with 414 runs, 13th with a .244 average and 10th with 85 homers. Second baseman Robinson Cano leads the way with an .842 OPS, 25 doubles and 59 RBIs. But his power is down with only seven homers in 103 games. Third baseman Kyle Seager has an .834 OPS, 25 doubles, 16 homers and a team-best 67 RBIs. Catcher Mike Zunino helps compensate for his .212 batting average with a team-leading 17 homers and 40 RBIs. Jackson and Denorfia should help add some production to the Mariners' outfield. Just like last weekend, the focus of this weekend will be on whether the Orioles' offense can break through enough against the stingy Seattle pitching staff. Before a 6-5 win in Cleveland last night, the Mariners had allowed four runs or less in nine straight games, only once allowing more than three during that stretch. Looking to add to a slim 1 1/2-game lead on first place in the AL East, Baltimore's arms will just have to be better as they were last weekend in Seattle.