Cubs spring preview: Infield

Starlin Castro led the National League with 207 hits last season. Jonathan Daniel/Getty Images

With pitchers and catchers reporting to Mesa, Ariz., on Saturday, Bruce Levine previews the Cubs roster by position this week.

By midseason, the Cubs should have one of the youngest and cheapest infields in the major leagues. First baseman of the future Anthony Rizzo is set to begin the season at Triple-A Iowa. That said, do not be surprised if he is promoted by the middle of May. The infield of Rizzo, Darwin Barney, Starlin Castro and Ian Stewart will be very young -- with an average age under 25 -- and cost an average of $1 million per player. Pacific Coast League MVP Bryan LaHair will be the Cubs’ starting first baseman on Opening Day.

First base: The 29-year-old LaHair hit 38 home runs last season at Iowa while driving in a minor league-high 109 runs. LaHair is a nice story about a player who refused to accept the notion that he was an extra player at best. He will get a window of time to prove just that to the Cubs' new front office and manager. Rizzo is waiting in the wings for his chance to play.

Second base: Barney played his way on to the Cubs' roster and into the starting lineup with guts and heady play, batting .276 last season as a rookie. After fading the last two months of 2011, Barney tried to add muscle mass in his offseason workouts. He will be pushed by new addition Adrian Cardenas, who was picked up in February off Oakland's roster. Cardenas has a solid bat and will factor somehow in the teams infield mix.Blake DeWitt was designated for assignment, but he could still show up as a non-roster invitee.

Shortstop: Castro, 21, will have to put off-the-field issue behind him -- he was accused of sexual assault last fall -- as he tries to become one of the elite players in the game. Castro, who led the National League in hits with 207, should begin to hit for more power and settle in to the third slot of Dale Sveum's lineup. Although he is a free swinger, the sky is the limit for the talented Castro. Do not be shocked by an MVP-like season from this young superstar.

Third base: Former Rockies first-round draft choice Stewart will man the hot corner for the Cubs coming out of spring training. Stewart had two injuries that hampered his performance in 2011 when he batted .156 in 122 at-bats. Stewart, who hit 25 home runs with 70 RBIs in 2008, came to the Cubs in a trade that sent Tyler Colvin and DJ LeMahieu to Colorado. A steady defender, Stewart will be hitting coach Rudy Jaramillo's pet project this spring. Veteran Jeff Baker backs up Stewart as well as Barney and LaHair. Baker is a super utility guy who can play anywhere in the infield or outfield. Josh Vitters, a 22-year-old prospect, made some progress in the minors last year, hitting 14 home runs and driving in 81. The Cubs' top draft pick in 2007, Vitters is not yet a finished product and still needs to upgrade his defense to advance to the majors.