Murton was batting .252 (30-for-119) with one home run and eight RBIs in 49 games for the Cubs.
"It's a chance for me to go out there and get consistent at-bats, to get back in the batter's box and do the things I'm capable of doing," Murton said. "For me, 100 broken-up at-bats over two months will not define a player. I'm a young player and I should continue to get better."
Murton batted .297 in 144 games last season with the Cubs, with 13 homers and 62 RBIs. But he also played left field. With the addition of Alfonso Soriano, Murton shifted to right field, which was already crowded with Jacque Jones and Cliff Floyd.
"You roll with it," Murton said of the switch. "I definitely was not as comfortable as I would have liked to have been [in right]. I'm athletic enough that, given time, I'll be adequate. I'll never be outstanding in right field. I think I can be above average in left, given work and given time. At the same time, it's not always the easiest thing to do in the beginning of the season.
"All things aside, as a baseball player, you have to find a way to go out there and get it done," he said.
The Cubs' bullpen has been working overtime. Jason Marquis lasted less than two innings Saturday, Ted Lilly threw 10 pitches before he was ejected on Sunday, and the team played 13 innings Tuesday night against the Seattle Mariners.
"We had to get a pitcher in here to protect ourselves a little bit," Cubs manager Lou Piniella said. "We won't need 13 pitchers for long."
Rapada was 2-1 with a 3.77 ERA in 29 relief appearances for Iowa, including a perfect 9-for-9 in save situations. He has held opponents scoreless in 23 of his 29 outings, and stranded 16 of 20 baserunners.
The left-hander, who impressed the Cubs this spring, was sharing the closer duties with Rocky Cherry and Randy Wells.
"[Piniella] gave me a boost of confidence," Rapada said of Spring Training. "After my first rough outing, he was real proud of me and said, 'You bounced back and showed you had a lot of confidence and showed a lot of character.'"
Piniella said Murton simply needs to play.
"He can help us if he's swinging the bat, and we think he will," Piniella said.
While Piniella said he felt Murton had changed his swing from last season, the outfielder said no.
"I'm always under the belief that no matter how good you are, you can continue to get better," he said. "My swing has not changed, my approach has not changed. Any player you look at in baseball, they make adjustments from day to day."
This spring, Murton said he felt good at the plate, and had addressed some of the things the Cubs wanted him to take care of, such as hitting for more power. He also played left, because Soriano was playing in center field.
"I came into the season feeling good," Murton said, "and here we are two months later."
He will play right field for the Iowa Cubs.
"I don't look at this as a negative in my mindset," Murton said. "It is what it is. It's a business. Baseball is a game in which you give your best effort each and every day. Some days it's good enough, sometimes it's not.
"I don't think that 100 at-bats dictates what a player is capable of doing, especially after what they've done in their previous at-bats," he said. "At the same time, in the market we're in here, and the team we have, and the un-met expectations at this point, there are going to be moves made, and I'm the move."
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.