After Jon Lester walked off the moudn with trainers and reports came out about tightness in his lat, immediate concern came up in Chicago. But good news came down on Friday when the team officially diagnosed Lester with shoulder fatigue and placed him on the 10-day disabled list.

Mike Montgomery, who pitched four-plus innings of relief of Lester, will slide into Lester's rotation spot while he is on the mend. The good news for Chicago, is Lester's absence is only expected to put him out of action for a week or two.

Before his injury, which seemed to clearly impact his horrendous start against the Cincinnati Reds in which he allowed seven earned runs in 1 2/3 innings pitched, the 33-year-old lefty held a 3.99 ERA. While it isn't the type of number many grew used to from the ace in his career, Lester's 3.69 FIP and 3.57 xFIP demonstrated some bad luck hurt him along the way.

After the All Star Break, Lester started to pitch to his normal lines again. In his last six starts before the outing in Cincinnati, Lester registered a 3.26 ERA and 2.93 FIP across 38 2/3 innings pitched. For a Cubs team clinging to a lead in the N.L. Central, the return of the team's ace meant a lot as they pushed deeper into the second half.

If Lester can return in the minimum amount of time and regain his form, Chicago should be set to try and hold on to its lead and seek that ticket to make it into the playoffs and the chance to defend its title.