Updated

Facing their largest deficit in nearly three months, the Washington Nationals are hoping Stephen Strasburg's return from the disabled list can kick-start a playoff push.

Chasing down NL East-leading New York will be more manageable, however, if Strasburg can dominate like he did right before landing on the DL and not pitch like he did in the season's first two months.

Strasburg takes the ball for the first time since Independence Day as the Nationals try to bounce back from a discouraging loss to the last-place Colorado Rockies on Saturday night.

Washington (56-52) was well on its way to a win Friday with a 4-1 lead in the eighth inning before Carlos Gonzalez hit a grand slam off former closer Drew Storen, sending the Nationals to a 5-4 loss. It was the sixth defeat in eight games for Washington, which fell 2 1/2 games out of the division lead for the first time since May 12.

''I guarantee none of the teams in our division feel sorry for us. The Mets are happy,'' Danny Espinosa said. " ... For us, we've just got to keep going, keep plugging and go day-to-day and try to get wins.''

A win Saturday will come much easier if Strasburg (5-5, 5.16 ERA) can pick up where he left off before getting injured.

Strasburg recorded a 6.55 ERA in his first 10 starts with the Nationals losing seven times before going to the DL on May 30 due to neck tightness. At the time of his injury, his ERA was the second-highest among the 116 pitchers with at least 45 innings thrown.

A five-week stint on the DL seemed to work wonders as he came off pitching like an All-Star.

The right-hander posted a 1.50 ERA with 15 strikeouts over 12 innings in winning his first two starts and was again pitching well in his third. He had allowed one hit over 3 2-3 scoreless innings against San Francisco on July 4 before hurting his side. He went on the DL the next day with a strained left oblique.

Strasburg was getting knocked around before his first injury, as opponents had a .497 slugging percentage, and struck out 20.7 percent of the batters he faced. The top pick of the 2009 draft was once again overpowering batters after coming off the DL, striking out 30.0 percent of hitters and holding batters to a .232 slugging percentage.

Replicating that kind of success won't be easy against a Rockies team which is averaging an NL-best 4.6 runs and is second in the majors in slugging at .442.

Gonzalez is 7 for 18 with two homers, two doubles and seven RBIs in his last five games and leads the league with 19 home runs since June 1. Nolan Arenado is second on that list with 14 but is 0 for 5 lifetime against Strasburg.

DJ LeMahieu, fifth in the NL with a .319 average, is 4 for 9 with a homer lifetime in their matchups.

"Our guys fight to the final out,'' Colorado manager Walt Weiss said. ''We've had some really tough losses ... but our guys continue to fight."

Strasburg went 1-1 with a 3.46 ERA against the Rockies (46-61) last season. He is 2-1 with a 1.74 ERA in three career home starts against them.

Colorado rookie Eddie Butler (3-8, 5.45) is being pushed up a day to make his first appearance against Washington in his fourth start since being recalled from Triple-A Albuquerque.

The right-hander is 0-2 with a 7.80 ERA since a seven-week stay in the minors and yielded three homers over four innings in Monday's 8-7 loss to Seattle.