Chicago @ Houston preview

Last Meeting ( Aug 16, 2011 ) Chi. Cubs 5, Houston 6

THE STORY: Owner of the worst record in baseball, Houston will attempt to build on Tuesday's thrilling walk-off victory when it hosts the Chicago Cubs in the final game of a three-game series on Wednesday afternoon. The Astros, who had lost seven in a row, stormed back for a 6-5 win against Chicago closer Carlos Marmol, closing the game on a one-out grand slam by Brian Bogusevic in the bottom of the ninth inning. The Cubs had won 12 of 15 games prior to Tuesday's setback.

TV: 2:05 p.m. ET, WGN (Chicago), my-20 (Houston)

PITCHING MATCHUP: Cubs RH Casey Coleman (2-4, 7.23) vs. Astros RH Bud Norris (5-8, 3.55)

Coleman has been largely ineffective in his nine spot starts this season, but he'll be getting the ball on a regular basis with Carlos Zambrano on the disqualified list. Winless since May 19, Coleman has hit the six-inning mark just once, back on May 7 against Cincinnati, and he has had a pair of starts in which he was knocked out before the end of the third inning. Strangely, Coleman is 1-0 with a 2.77 ERA in two career starts against Houston.

Norris has been one of the few bright spots for the Astros this season, but he has been kept out of the win column since July 6 despite three quality starts, including a brilliant effort in his last outing (7 IP, 2 H, 0 R, 8 K in a 1-0 loss at Los Angeles). Norris allowed just one earned run in his last start against the Cubs on July 22, but three unearned runs doomed him to a 4-2 defeat. He is 1-2 with a sterling 1.69 ERA in four career games (three starts) against Chicago.

ABOUT THE CUBS (54-69): Tuesday night's meltdown was nothing new for Chicago — Marmol's eighth blown save tied him for the major league lead, and the Cubs' vaunted bullpen has failed to convert on 18 of their 50 save opportunities this season. The relief corps has been just part of the problem — Chicago ranks at or near the bottom of the National League in every major pitching category, including quality starts (just 52 in 123 games). The offense has scored 88 runs in the last 16 games, with 3B Aramis Ramirez (13 for his last 26) leading the charge.

ABOUT THE ASTROS (39-84): Houston won for just the 16th time in its last 66 games, and it needed pinch-hit heroics Tuesday from a player (Bogusevic) who has done two minor-league stints during the season. The Astros have been trying to piece their lineup together since dealing star outfielders Hunter Pence and Michael Bourn in late July, but the results have been slow in coming — the team is just 4-11 in August, scoring just four runs in its last four games before Tuesday's win. 1B/OF Carlos Lee (.260, 11 HR, 68 RBIs) has been one of the few mainstays in an ever-changing lineup.

FINAL PITCH: As bad as Chicago's bullpen has been at holding leads, the Astros have been even worse. Houston has converted just 15 of 36 save opportunities, easily the lowest rate in baseball.