Erik Johnson in express lane to Chicago

If it wasn’t for a minor injury that kept him off a mound for 25 days last month, perhaps Erik Johnson would be starting for the Chicago White Sox at Kansas City on Wednesday instead of Andre Rienzo.

Johnson, currently the brightest pitching star in the White Sox’s system, is showing that he is ready for a major league promotion despite a disabled list stint in July.

On Monday night Johnson gave up seven hits over eight shutout innings in Charlotte’s 1-0 victory over Durham. It meant that in eight starts with the Knights since being promoted from Double-A Birmingham, the 6-foot-3, 235-pound right-hander has a 1.59 ERA.

Combined with the 2.23 ERA at Double-A, not to mention an 8-2 record, Johnson has a combined 2.01 ERA in 22 minor league starts this season, using a fastball in the mid-90s to go along with a slider and a developing changeup. He also has a curveball at his disposal.

The 23-year-old, who is a native of Mountain View, Calif., spent just over three weeks on the DL with a groin injury. He returned July 28 with a short 2 1/3-inning stint to build back his arm strength.

The timing of the injury was costly for Johnson since the White Sox needed a starter on July 30 as they worked out the details of Jake Peavy's trade to the Boston Red Sox. Manager Robin Ventura admitted that Rienzo was picked over Johnson to take over Peavy’s old rotation spot in part because Johnson was just getting back from the DL.

It appears, though, that Johnson’s wait to reach the big leagues will be ending soon. Rosters expand Sept. 1 and Johnson is expected to be a part of the group of prospects that arrives next month. He was the White Sox's second-round pick in 2011 out of Cal.

How the White Sox use Johnson remains to be seen. He could be used in relief, as many starters are when they reach the major leagues. Bringing him out of the bullpen gives him a taste of the major leagues, while also keeping his innings in check.

Or he could be used as a starter, which would help make up for time missed on the DL. The White Sox would have to find him a rotation spot, though, and they have already said that Chris Sale won’t have restricted innings this year. Johnson already has a combined 130 innings this season.

One plan to get Johnson starts could be to shut down John Danks, who is returning from shoulder surgery this year, although the White Sox might prefer that the left-hander continues to start after missing a year of action.

In any event, Johnson will be Chicago-bound very soon, having not given up more than two runs in any of his eight starts at Charlotte and giving up one run or less in six of them.