CHICAGO -- It's been one week since Matt Garza was diagnosed with a stress reaction in his right elbow, and he may simply run out of time this season to recover.

"There's no need to rush him back," said Theo Epstein, president of baseball operations. "Let him heal and put him in a position to be 100 percent so he can have a big year next year for the Cubs."

Garza last pitched on July 21, and left that game with cramping in his right triceps. He was diagnosed with the stress reaction on Aug. 6.

Manager Dale Sveum said on Tuesday that he would be surprised if Garza returns. The right-hander has not been allowed to pick up a baseball since the diagnosis.

"It'll be kind of tough," Sveum said about Garza coming back. "Some guys heal quicker than others."

Garza was 5-7 in 18 starts, with a 3.91 ERA.

"In his mind, he wants to come back and pitch," Sveum said.

Jackson working through big league growing pains

CHICAGO -- Not everybody can be Mike Trout. Brett Jackson is discovering that. The young outfielder has struck out 14 times in 24 at-bats in the week he's been in the big leagues.

"There's a long line of great players, including Hall of Famers Mickey Mantle and Willie Mays, who ... were 1-for-55 their first years in the big leagues," Theo Epstein, president of baseball operations, said on Tuesday. "We almost expect young guys to come up and struggle. It's part of the growth process. It doesn't make it any easier for them to go through, but it's a natural step in a player's development. They come up and get humbled a little bit and make their adjustments, and maybe you have a chance to humble someone else down the line."

For the record, Trout, the Angels' stellar outfielder, also scuffled at the start, going 1-for-11 in his first three games.

Jackson, promoted from Triple-A Iowa on Aug. 5, spent some extra time in the batting cage with hitting coach James Rowson prior to Tuesday's game.

"One of the things I told [Jackson] when he got here was that I didn't want to get into a whole lot of mechanics," manager Dale Sveum said. "I want him to go out and play and we'll evaluate from there and see what's going on. You don't want to sit there and tell somebody -- especially a young kid trying to survive in the big leagues -- mechanics, mechanics, mechanics. You can't concentrate on hitting or the baseball."

One of the things Sveum has noticed is that Jackson needs to fix what he dubbed a "lazy head." The Cubs want to see his head stay focused on the baseball longer.

"When [good hitters] swing the bat, their heads drive down and their nose gets much closer to the baseball than when it started," Sveum said of such players as Derek Jeter and Wade Boggs. "These are things that have to happen on a consistent basis. Every great hitter, consistent hitter does that with their head."

Jackson, the Cubs' No. 1 Draft pick in 2009, was hitting .256 with 158 strikeouts in 106 games at Iowa before he was promoted. In his first game, on Aug. 5 against the Dodgers, he went 2-for-4 with two singles. He has one hit in 20 at-bats since then.

"Sometimes to survive, you have to hit rock bottom and get back up," Sveum said. "This game is full of adversity. The guys who usually make it are able to handle the adversity and make adjustments. That's part of what we're doing this for in the evaluation process."

Extra bases

• Outfielder Albert Almora, the Cubs' No. 1 pick in this year's First-Year Player Draft, was promoted from the Mesa Rookie League team to Class A Boise, and is expected to join the Hawks on Wednesday.

Almora went 5-for-6 on Monday to lead a 25-hit attack and help Mesa beat the Reds, 17-7. Almora batted .413 over his last 10 games.

"He's done a real nice job the last week to 10 days," said Theo Epstein, president of baseball operations. "For him it was a matter of getting his timing down. He has a leg kick, and sometimes those guys have to see a lot of live pitching to get their timing locked in. He can drive the ball all over the field recently. We think he's pretty advanced for an 18-year-old."

• Casey Coleman, who was pitching for Triple-A Iowa, was placed on the disabled list with a strained right shoulder, and Cuban pitcher Yoanner Negrin has been promoted to Iowa from Double-A Tennessee. Negrin was signed as a non-drafted free agent in 2011 and began this season with Omecas de Tabasco of the Mexican League. He made one start for the Smokies and did not give up an earned run over five innings.

• Alfonso Soriano is two shy of 1,000 RBIs for his career. He looks to become the sixth player in Major League history to total 1,000 RBIs, 400 doubles, 350 home runs and 250 stolen bases. The others are Barry Bonds, Andre Dawson, Willie Mays, Alex Rodriguez and Gary Sheffield.