The Chicago Cubs have been great in the standings so far this season, but they haven't been able to catch a break in the starting rotation. Both Cade Horton and Justin Steele are on the 60-Day Injured List. On Wednesday, ESPN's Jesse Rogers reported that Matthew Boyd is set to undergo surgery due to a left meniscus injury that he suffered while sitting down to play with his kids and that his timetable to return is unknown. "Cubs P Matthew Boyd to have surgery after a left meniscus injury, per Craig Counsell. Timetable unknown right now," Rogers wrote. "Injury happened sitting down to play with his kids." Boyd is on the 15-Day Injured List after making five starts for Chicago on the season so far. Overall, he has a 6.00 ERA in 24 innings pitched. Last season, Boyd was an All-Star for the Cubs and logged a 3.21 ERA in 31 starts across 179 2/3 innings pitched . With Boyd joining the growing list of Cubs hurlers on the shelf, who could replace him? Here are four options.…