Washington @ Colorado preview

Last Meeting ( Jun 27, 2012 ) Washington 11, Colorado 5

Following Monday’s 4-2 series-opening loss to the Colorado Rockies, the Washington Nationals had scored 25 runs during a 10-game stretch in which they went 3-7. In their last two games, though, they have scored 23 as they seemed to realize they were playing at Coors Field, where slumps always seem to die. Washington will try to make it three straight wins when it concludes its four-game set with Colorado on Thursday.

The offensive surge has been led by Ryan Zimmerman, who is 8-for-17 in four games since receiving a cortisone shot in his right shoulder (inflammation) prior to Sunday’s game. He had a homer and three RBIs in Wednesday’s 11-5 victory.

Washington, which leads the National League East by 3 1/2 games over the Atlanta Braves, has a major league-best 2.98 ERA. The Rockies, who have lost eight of their last nine games at home and 16 of 20 overall, have baseball’s worst ERA at 5.43.

TV: 3:10 p.m. ET, MASN (Washington)

PITCHING MATCHUP: Nationals RH Edwin Jackson (4-4, 2.94 ERA) vs. Rockies LH Josh Outman (0-3, 8.64)

Jackson took a perfect game into the fifth inning before allowing one run and four hits in a 3-1 victory at Baltimore on Saturday. Jackson has won three of his last four outings and has a string of seven straight quality starts. The Rockies’ roster is hitting .389 against Jackson, with Carlos Gonzalez, Michael Cuddyer and Todd Helton a combined 13-for-26.

Outman threw a season-high 92 pitches in his last start, when he allowed five runs and eight hits in 4 2/3 innings but didn’t receive a decision in Colorado’s 11-7 victory at Texas on Saturday. Outman will be making his sixth start of the season and hasn’t pitched more than five innings. After pitching 3 1/3 shutout innings and striking out eight in his first start, Outman has allowed at least four runs in each of his last four outings.

WALK-OFFS

1. Washington, which has 35 hits in its last two games, scored as many as nine runs once in its first 71 games prior to Tuesday.

2. Colorado LHP Jorge De La Rosa, who hasn’t pitched since last June before undergoing Tommy John surgery, will be shut down until at least September because of continuing elbow problems.

3. Zimmerman and teammate Tyler Moore have homered in each of the last two games.