Though Burnett has hit a rut, San Diego Padres starter Tyson Ross continues to shine.Burnett looks to bounce back from a couple of poor outings as he opposes Ross on Tuesday night at Petco Park.After going 2-1 with a 1.89 ERA over seven starts from June 8-Aug. 4, Burnett (5-8, 3.18 ERA) has struggled over his last two. He gave up five earned runs and eight hits in 5 2/3 innings of a 6-4 loss to Colorado on Aug. 10 before allowing the same numbers in just 4 1/3 frames of the Pirates' 6-5, 12-inning loss to St. Louis on Thursday.Manager Clint Hurdle, though, isn't worried about his right-hander, whose 3.38 run-support average is seventh-worst in the majors."There's some things we've tried to identify from the last start and from this start," manager Clint Hurdle said. "I know also he's a guy that's experienced everything there is in the game and he will be good and ready to take the ball the next time."It may not get much better for Burnett give his recent history against the Padres. He allowed 29 runners to reach base in 12 innings over two starts versus San Diego last year, yielding four earned runs in each outing.He walked five at Petco Park on Aug. 21, just his second start in San Diego since his nine-walk no-hitter in 2001 with the Marlins.Pittsburgh (73-51) got the best of the Padres in Monday's series opener, though, winning 3-1 after dropping 18 of the previous 21 meetings. Pedro Alvarez hit his NL-best 31st homer as the Pirates, who had lost seven of their previous nine, maintained their one-game lead on St. Louis and 2 1/2-game edge on Cincinnati in the NL Central race.Pittsburgh may find it tough to make it two straight victories when it faces Ross (3-5, 2.62).Ross has been stellar since rejoining the rotation July 23, going 3-1 with a 1.32 ERA in five starts. He allowed one run and five hits in seven innings before San Diego fell 4-1 to the New York Mets on Thursday."I'm just trying to improve on what I did the previous outing and just try and do better," Ross said.The right-hander has a 0.79 WHIP during his hot stretch while striking out 36 in 34 innings."He's throwing the ball great," manager Bud Black said. "I think he's really taken a lot of the instruction that he and (pitching coach) Darren (Balsley) are talking about as far as being able to locate the fastball, getting the slider in the strike zone and incorporating some changeups."Ross, in his first season with the Padres after being acquired from Oakland in November, has never faced the Pirates.San Diego (56-69), which has lost nine of 13, looks to provide some offense for Ross after going scoreless for the first eight innings Monday. Nick Hundley's double drove in Chase Headley for the Padres' only run.Headley, with only eight home runs and 35 RBIs after breaking out for 31 homers and 115 RBIs in 2012, is just 6 for 37 (.162) over his last nine.