One night after their ace let them down, the St. Louis Cardinals turn to one of their most inconsistent pitchers. With Shelby Miller on the mound Saturday, the visiting Cardinals hope to avoid losing to the last-place Philadelphia Phillies for the second straight night. Philadelphia improved to 3-1 on its homestand with a 5-4 triumph on Friday thanks to three hits from Ben Revere and two RBIs from Ryan Howard.Adam Wainwright failed to protect a 4-1 lead on Friday and lasted only six innings - a plateau Miller has surpassed just once in his last 10 starts. David Buchanan, who quietly has had a productive rookie season, gets the nod for the Phillies. Philadelphia, of course, is not close to playoff contention, but St. Louis enters Saturday's matchup 1 1/2 games behind first-place Milwaukee in the National League Central while sitting atop the wild-card standings.TV: 7:05 p.m. ET, FSN Midwest (St. Louis), CSN PhiladelphiaPITCHING MATCHUP: Cardinals RH Shelby Miller (8-9, 4.25 ERA) vs. Phillies RH David Buchanan (6-7, 4.25)Miller has given up nine runs in 11 innings over his last two starts and is coming off a 9-5 defeat against San Diego in which he issued a career-high six walks over six frames. Chase Utley and Howard are a combined 6-for-9 against Miller, who lost to the Phillies 4-1 on June 19. Howard hit a two-run homer in that contest to help ignite a stretch during which St. Louis has won just two of Miller's last 10 starts.Buchanan has gone nine straight starts without allowing more than three earned runs. Most of his success has come without the benefit of strikeouts, however, as he has not fanned more than six hitters in any of his 13 outings. One of the best starts of his rookie season came against St. Louis, when he opposed Miller on June 19 and gave up one run and four hits over a career-high 7 2/3 innings.WALK-OFFS1. Buchanan has allowed only five extra-base hits (two homers) in 126 at-bats against left-handed hitters.2. The Phillies' last six victories have come by a total of nine runs.3. Cardinals C Tony Cruz, filling in for the injured Yadier Molina, is 2-for-24 over his last eight games.PREDICTION: Phillies 5, Cardinals 3