The Orioles have won all four games after not playing the day before heading into Friday night's opener of a three-game home set against a Royals team that has struggled following time off.Baltimore (28-17) dropped two of three to Boston this week, capped by Wednesday's 6-5 defeat. That finished a 12-8, 20-day stretch for the Orioles, who had one day off in that span due to a postponement against Texas."I'm real proud of the effort and the way these guys have gotten after it for these 20 games," manager Buck Showalter said. "We knew looking at the schedule it was going to be a real challenge for us physically, mentally and emotionally."The Orioles won the first game of a doubleheader against the Rangers on May 10 following the rainout to improve to 4-0 coming off a day off, not counting another win on opening day.Kansas City (17-26) has lost all five times after not playing the day before, including two contests after postponements and not including an opening day defeat. The Royals, who've lost four straight in Baltimore, weren't well rested when they were swept in a two-game home set by the Orioles from May 16-17, with the opener going 15 innings.Adam Jones homered twice in that series, including the game-winner in the 15th. Jones is batting .355 during a career-best 15-game hitting streak in which he has six homers and 12 RBIs.Baltimore leads the majors with 69 homers and is 13-1 when Jones goes deep.Nick Johnson had his first multihomer game in nearly six years Wednesday. Johnson is 13 for 37 (.351) with four homers and 10 RBIs this month after his 0-for-26 April.Kansas City, meanwhile, has 33 homers for the AL's second-lowest total. The Royals, however, had their most longballs in a three-game set this season with five as they lost two of three to the Yankees this week.Jeff Francoeur had two homers while slumping Eric Hosmer went 5 for 11 in the Bronx.Jason Hammel (5-1, 3.12 ERA) will start Friday for Baltimore. He posted a 2.09 ERA in his first six outings, but knee pain has been a factor in his 6.97 mark over his last two.The right-hander surrendered four runs over 5 1/3 innings Saturday but got credit for a 6-5 win at Washington."Obviously, I want to be getting deeper into ballgames, but the knee is just not cooperating right now," Hammel told the Orioles' official website.Hammel is 0-2 with a 7.63 ERA in three career starts against the Royals.Kansas City's Bruce Chen (3-4, 4.17) is headed in the opposite direction, going 3-0 with a 2.75 ERA in his last three starts after beginning 0-4 with a 4.98 ERA. The left-hander gave up two runs over 6 1/3 innings Saturday in a 7-3 victory over Arizona.Chen is 2-1 with a 3.74 ERA in four starts against the team he pitched for from 2004-06. Jones is 5 for 11 against him with a homer.The Orioles lead the majors with a 7-3 record against southpaw starters.