CHICAGO -- Following back-to-back series with teams very much in the postseason hunt the Chicago Cubs now play three against teams far off the pace.While mathematically alive, the Milwaukee Brewers, Colorado Rockies and San Diego Padres are all playing sub-.500 baseball and trail leaders in their respective divisions by 10 1/2 games or more.The Cubs (73-43) swept a pair from the Los Angeles Angels last week and then split a four-game series with division rival St. Louis to maintain a 12-game lead in the National League Central.The Brewers and Cubs open a four-game series with Tuesdays day-night doubleheader at Wrigley Field. One game is a makeup from an April 27 rainout. Milwaukee (52-64) is fourth in the NL Central, 21 games behind Chicago.The Brewers bring in one of baseballs hottest bats in Ryan Braun, batting .381 with 26 runs, nine homers, 21 RBI and 14 walks since the All-Star Break.Hes really locked in and producing, for sure, said Brewers manager Craig Counsell. We were worried a little about what would happen after losing the hitter (Jonathan Lucroy) behind him but hes responded really well and hes certainly been swinging the bat great.The Cubs counter with a pitcher making his first start of the season in Tuesdays opener and a short-handed bullpen exposed in last weekends Cardinals series.Right-hander Trevor Cahill gets a spot start in Tuesdays 12:20 p.m. game against Brewers righty and ex-Cub Matt Garza (4-4, 4.83 ERA). Chicagos Jason Hammel (12-5, 2.90 ERA) carries a five-start winning streak into Game 2 against Milwaukees Chase Anderson (7-10, 4.93 ERA) at 7:05 p.m.Cahill will come off the disabled list and serve as 26th man for Tuesdays doubleheader. He has been sidelined since July 9 with patellar tendinitis in his right knee but made six recent starts with Triple-A Iowa, going 0-3 with a 4.58 ERA.He is 1/3 with a 3.07 ERA in 33 appearances with the Cubs this season.Bullpen weakness was a contributing factor in Cubs losses on Saturday and Sunday.Reliever Hector Rondon returned on Sunday after being out 12 days with a sore triceps. He gave up a go-ahead three-run homer to Stephen Piscotty in the eighth inning.His stuff wasnt as crisp as normal., Cubs manager Joe Maddon said. The fastball velocity wasnt up there. He obviously did not throw the ball where he wanted to.Pedro Strop is out four to six weeks after undergoing arthroscopic surgery last week for a left meniscus tear.Not having Stroppy -- we just have to figure this out, Maddon said. We have to restructure this somehow.Chicago also had another pitching scare on Sunday night when starter John Lackey departed in the seventh inning with shoulder stiffness.But Lackey said after the game that he was fine. He figures to start again later this week at Colorado.Im OK, he said after Sundays game. (An) extra bullpen session was probably not the best for me. I feel a little tight since then. Nothing crazy. Trust me. Ive been out there feeling a lot worse. Ill be all right. Yennsy Diaz Blue Jays Jersey . The Lightning are 2-0 so far on a four-game road trip, giving the club five straight wins as the guest and improving Tampas away record this season to 11-8-2. Reese McGuire Jersey . Peter Holland and Brad Staub