CHICAGO -- Akinori Iwamura hasn't come anywhere close to meeting the offensive expectations the Pirates had of the infielder when they acquired him over the offseason. Still, manager John Russell said he will continue starting the struggling second baseman, hopeful that Iwamura can start to find the offensive success similar to his time in Tampa Bay.

"We are looking for him to relax and just do what he's capable of doing," Russell said. "He's done it in the past. We just need him to relax and let it happen."

Iwamura's start has been extremely disappointing. He continues to hit primarily from the leadoff spot, despite a .161 batting average and a .255 on-base percentage. Those numbers have been even worse recently, as Iwamura, who went 0-for-6 on Friday vs. the Cubs, has gone just 2-for-41 since the start on May.

With the hits not falling, why not just take Iwamura out of lineup altogether? There's a few reasons why the Pirates have opted not to do this just yet. Iwamura's lengthy track record shows that he has hit everywhere he's been, and the organization isn't ready to concede that Iwamura can't still do that with Pittsburgh. Also, the decision to stick the team's highest-paid player on the bench is never one made lightly.

"While Iwamura's standard statistics are not at the levels we anticipated, his objective numbers indicated a heavy slant toward small sample size and bad luck over regressing skills," general manager Neal Huntington said. "One such metric is his BABIP [batting average on balls in play], which is below .200 for 2010 to date, while his prior low single season was .337. Combine small sample size with changing leagues and recovery from a significant injury, and it is way too early to begin to panic about Aki's performance to date."

Furthermore, Russell hasn't seen anyone else step up to seriously challenge Iwamura for the chance to play every day. Delwyn Young, who could play the position, has hit just .194 as a starter this season. Backup infielder Bobby Crosby is hitting only .211 when in the starting lineup.

"We've tinkered with the lineup a little bit, and it's not like anybody else is really doing a lot either," Russell said. "We've got to do this as a team. It's not one guy. Aki not getting on base is not the whole reason why we're not scoring runs. We've got to be careful pointing the finger at one guy or even two guys."

What this doesn't address are the Pirates' two other potential long-term options, neither of which the Bucs have tapped into yet. There have been discussions about moving Andy LaRoche to second when top prospect Pedro Alvarez is ready for the Majors. To this point, LaRoche has not taken grounders at second. That suggests he's not going to be making that transition soon.

The other option is Neil Walker, a former first-round Draft pick who is thriving down at Triple-A Indianapolis. Walker is leading the International League with 45 hits, but management's apparent disappointment with Walker's attitude and effort could postpone his callup, even though the Pirates appear to have a need.

Donnelly progressing after latest session

CHICAGO -- Right-hander Brendan Donnelly (left oblique strain) threw a 25-pitch bullpen session off the Wrigley Field mound on Friday and reported feeling physically fine afterward. Donnelly is scheduled to throw a second side session on Sunday before pitching in a simulated game during Pittsburgh's upcoming series in Philadelphia.

If all goes as expected, the Pirates plan to activate Donnelly off the disabled list when they return home later next week. Donnelly last pitched on April 27 against Milwaukee.

In other injury news:

• Manager John Russell said he plans to insert outfielder Ryan Church back into the starting lineup on Saturday. Church has been nursing a bruised right wrist since being hit by a pitch on May 7. He is cleared to pinch-hit, and Russell said that Church has improved enough over the past few days that he could take multiple at-bats on Friday if needed.

• Shortstop Ronny Cedeno returned to the Pirates' lineup after missing Wednesday's game with a sore left wrist. Cedeno suffered a bruised wrist after getting hit by a pitch from Reds starter Johnny Cueto on Tuesday.

Pearce day-to-day with knee injury

CHICAGO -- First baseman Steve Pearce was sent to Northwestern University hospital on Friday afternoon and underwent an MRI on his right knee. The results were negative, and he's listed as day-to-day.

Pearce exited Friday's 10-6 victory over the Cubs after feeling a pop behind his knee and then complaining of soreness in that spot. The injury occurred while Pearce was on first base after drawing a fifth-inning walk.

Pearce felt the pop, manager John Russell said, as he took off for second on a foul ball hit by shortstop Ronny Cedeno. Pearce called for the Pirates' trainers, and he tested his leg out with a few sprints up the right-field foul line. He remained in the game for a few more pitches, but after Cedeno walked, Pearce was removed for a pinch-runner, pitcher Zach Duke.

By the time the game ended, Pearce was unavailable for comment.

Pearce was making his fourth start for the team since being called up on May 4. He entered the game 2-for-13, but tallied his first RBI of the season with a first-inning sacrifice fly off Tom Gorzelanny.

Updates from down on the farm

CHICAGO -- Here are some notable items from down on the farm:

• The Pirates plan to promote right-hander Bryan Morris to Double-A Altoona soon, which shouldn't come as much of a surprise given his dominance at high Class A this season. Morris has not allowed an earned run in any of his past four starts (26 innings) and has surrendered three in 40 2/3 total innings. The right-hander has struck out 36 and walked five in Florida State League play.

• Right-hander Quinton Miller remains shut down with biceps tendinitis and is expected to miss about a month more of action. Miller, a 20th-round selection in the 2008 First-Year Player Draft, made two starts for low Class A West Virginia before being sidelined with the injury. He allowed one run on five hits in six innings.

• With a four-hit game on Thursday, Triple-A utility player Neil Walker pushed his season average up to .338. Twenty-three of his International League-leading 45 hits have gone for extra bases, and Walker has driven in 24. With 43 hits, Walker's teammate, Jose Tabata, is second among league leaders in that category.

• Left-hander Donnie Veal made his shortest start of the season on Thursday, lasting just 4 2/3 innings and giving up three earned runs on six hits. Veal struck out six to up his season total to 28 in 37 2/3 innings.

Worth noting

According to the Elias Sports Bureau, three times this season one team has recorded at least 14 more hits than its opponents. Twice, the Pirates have been on the wrong end of that distinction. Pittsburgh was outhit, 25-8, by Milwaukee on April 22. They were then outhit, 15-1, by the Reds on Tuesday. ... Friday's game marked the first of 20 games in 20 days for the Pirates, whose next off-day is scheduled for June 3. ... The "You score as the Bucs score" promotion kicked off on Friday. The Pirates will tally up each run scored by the team in its three-game series vs. the Cubs and take that off the price of a $24 right- or left-field box-seat ticket when the Pirates host the Braves from May 21-23. A limited number of tickets have been set aside for this promotion. More details can be found at: www.pirates.com/howmanyruns.