Clinching a third straight playoff appearance would be quite an accomplishment for a club that couldn't even crack the .500 mark in the previous 20 years.

The Pittsburgh Pirates still are looking for more than just another wild-card berth, but time is running out.

They can secure a postseason spot Tuesday night with a win over the Colorado Rockies at Coors Field and some help.

More from FoxSports

Pittsburgh (90-60) hadn't been to the playoffs since winning the last of three straight division titles in 1992 before hosting the first of two straight wild-card games in 2013.

If the Pirates beat the Rockies (63-87) in this contest, Washington falls to Baltimore and San Francisco loses at San Diego later Tuesday, they would be assured of reaching the playoffs once again. However, overcoming the four-game NL Central deficit to St. Louis with 12 to play and avoiding the one-game playoff would be ideal.

Pittsburgh has won three of four to begin a 10-game road trip after beating Colorado 9-3 on Monday. Starling Marte went 4 for 5 while homering for the second straight game, and Aramis Ramirez also went deep.

The Pirates remained two games ahead of the Chicago Cubs for home-field advantage in a potential wild-card matchup.

''It's an organizational win,'' manager Clint Hurdle said of Pittsburgh reaching 90 for the second time in three years.

Acquiring J.A. Happ (5-2, 1.96 ERA) has proved to be one of the best under-the-radar moves at the trade deadline. Happ's five-start winning streak came to an end last Tuesday even though he held the Cubs to two runs in 5 2-3 innings of a 2-1 loss.

The left-hander has struck out 26 in 18 2-3 innings over his last three outings and has a 1.30 ERA over his last seven.

"A few pitches caught too much plate and they hit a couple doubles," Happ said after his last outing. "Just tried to zone back in and execute your pitch and be able to mix it up a little bit. For the most part, we were able to do that."

Happ was effective against the Rockies on Aug. 29, giving up one run in 5 2-3 of a 4-3 victory. He beat Chris Rusin (5-8, 5.11), and they'll face each other again in this contest.

Rusin gave up three runs in six innings in the last matchup and had that same line in Colorado's 5-4, 16-inning win over the Los Angeles Dodgers last Tuesday.

The left-hander has a 9.00 ERA in five starts since shutting out San Diego on Aug. 16. Ramirez (4 for 11 with two homers), Pedro Alvarez (4 for 11) and Andrew McCutchen (4 for 12 with a homer and a double) all have had success against Rusin.

Colorado has dropped back-to-back games after losing for the third time in four meetings with Pittsburgh. Former Pirate Justin Morneau went 3 for 4 and is batting .476 with two triples and two doubles over his last six.

Nolan Arenado is hitless in nine at-bats over his last two after going 8 for 18 over his previous four. Carlos Gonzalez is batting .095 over his last six.

Charlie Blackmon's two stolen bases Monday gave him 40, making him the first Colorado player to reach that mark since Willy Taveras in 2008.

''He's always run pretty well but he's done a nice job of preparing every night to steal bases," manager Walt Weiss said. ''Forty stolen bases is a lot in this day and age.''