By MATT BEARDMORE
(AP) -- The Washington Nationals have a big hole to fill in their lineup with slugger Michael Morse gone.
Third baseman Ryan Zimmerman hasn't done much to make up for that loss, but Adam LaRoche and Ian Desmond are doing their part.
The Nationals look to extend the franchise's best start in 11 years Friday night when they continue their series against the visiting Cincinnati Reds.
Tied for ninth in the NL last season with 31 homers and 10th with 95 RBIs, Morse isn't expected to make his season debut for quite some time after the Nationals announced Thursday that their cleanup hitter re-aggravated an injured right lat muscle during Monday's game at Single-A Hagerstown.
"We are going to put him on total shut-down mode for six weeks, so he can rest it," general manager Mike Rizzo told the Nationals' official website. "We'd tried to ramp him up and get him ready as quickly as we could, because he is a big piece of our lineup."
So is Zimmerman, but he's batting .192 with two RBIs.
The former Gold Glove winner, who was hit by a pitch then scored the winning run off an Alfredo Simon wild pitch in Thursday's 4-3, 10-inning series-opening victory, is also having issues in the field.
Zimmerman committed an error in the third inning Thursday then couldn't come up with a ball hit by Ryan Ludwick in the ninth when the Reds scored twice to tie it.
"If we had lost that game," Zimmerman said, "it would have been hard for me to sleep tonight."
Washington (5-2) is off to its best start since the Montreal Expos opened 6-2 in 2001, and while its 2.18 ERA deserves much of the credit for the success, LaRoche and Desmond have been key contributors at the plate.
LaRoche drove in two runs Thursday and is hitting .345 with two homers and a team-best eight RBIs. Desmond's average jumped to .406 with a 3-for-5 effort in the home opener.
The Nationals continue their 11-game homestand with Jordan Zimmermann (0-1, 1.29 ERA) on the mound. The right-hander yielded one earned run in seven innings of Sunday's 4-3 loss at Chicago.
"I was able to locate the fastball pretty well, and the curveball and slider were both there today," Zimmermann said.
Zimmermann faced the Reds twice last season, going 1-0 with a 2.70 ERA. He went 5 2-3 scoreless innings in his only home appearance, a 3-1 victory Aug. 18.
Bronson Arroyo (0-0, 5.68), who took the loss in that game after throwing six innings, gets the ball for Cincinnati (3-4) on Friday.
With the Reds scoring eight runs while losing three of their last four games, the veteran right-hander might have to be sharper than he was in a 6-5 victory over Miami on Sunday when he was tagged for five runs and 10 hits over 6 1-3 innings.
Arroyo is 1-2 with a 4.56 ERA in four starts at Washington.
Reds second baseman Wilson Valdez, 3 for 5 with two doubles off Zimmermann, will likely make a third consecutive start with Brandon Phillips not expected back until this weekend due to a hamstring injury.
Updated April 12, 2012