A lot of attention has been paid to the Cubs' pitching staff this season, and the praise is rightfully deserved. The five-man ensemble of Jake Arrieta, Jon Lester, Kyle Hendricks, John Lackey and Jason Hammel has been spectacular so far, with all five pitchers sporting ERAs under 3.00 and WHIPs under 1.10. Four of the Cubs' five starters rank in the top 5 in WHIP, with the Dodgers' Clayton Kershaw touting a league-best 0.65.
Clearly the Cubs don't need any starting pitching help. And with that in mind we turn our attention to the bullpen. Hector Rondon has been excellent, while Pedro Strop, Trevor Cahill, Travis Wood and Adam Warren have been solid for the most part. However, Justin Grimm has regressed after a very good 2015 season and Clayton Richard will almost certainly be designated for assignment in the future.
The Cubs' biggest need in the bullpen is a lefty like the Yankees' Andrew Miller, someone who could serve not only as a specialist, but an impact arm who could finish an inning unscathed. But as the season wears on, some players may become susceptible to the injury bug. The Cubs have lost Jorge Soler and Tommy La Stella to hamstring injuries just this week, and Matt Szczur, Jason Heyward and Miguel Montero have already missed some time due to injuries.
Obviously there aren't many needs in the bullpen right now, but if worst comes to worst, who can the Cubs call upon to provide a lift in the immediate or near future? What about in September? Let's take a look at some of the Cubs' best options from inside their own farm system.
1. Carl Edwards Jr.
Edwards Jr. is a reasonable first choice to be called up from Triple-A. The 24-year-old was brought up to serve as the Cubs' 26th man in their doubleheader against the San Diego Padres, and he's been really good over the past several weeks for the Iowa Cubs minus a pair of recent hiccups. Control has always been a concern for Edwards Jr., but hitters are batting a measly .152 against him this season. However, he's walked the bases loaded in two of his last four outings.
2. Gerardo Concepcion
With Richard clinging on to a roster spot by a thread, a lot of noise has been made for the Cuban lefty to take his place in the Cubs' bullpen. Concepcion threw 17.2 innings at Double-A Tennessee without allowing a run to start the 2016 season, and since his promotion to Triple-A Iowa he's thrown 11.2 innings, posting a 2.31 ERA, 1.37 WHIP and .195 opponent batting average. His control hasn't been as sharp as it was in Tennessee, but that could just be him settling into his new role in Iowa. If Richard continues to give up runs and the Cubs fail to acquire an impact lefty at the deadline, look for Concepcion to be a potential replacement.
3. Armando Rivero
While he's 28 years old and hardly a prospect, Rivero has thrown 10 straight shutout innings at Triple-A Iowa with 19 strikeouts and six walks during that span. This is the Cuban's third consecutive season with the Iowa Cubs, but with a .161 opponent batting average and 12.2 K/9 ratio in 2016, he still has a chance to find his way to the Cubs or another major league roster if he keeps the walks down.
4. Felix Pena
Pena has been a breakout performer for the Iowa Cubs this season, posting a 1.29 ERA and 0.71 WHIP through 28 innings with 34 strikeouts, eight walks and a .126 opponent batting average. The 26-year-old has been arguably Iowa's best middle reliever this season, and with the Rule 5 Draft coming up this winter, the Cubs will have a decision to make regarding his future with the organization.
5. Corey Black
Black was promoted to Iowa from Tennessee on Thursday after recording nine saves and a 3.18 ERA with 25 strikeouts and a .220 opponent batting average in 22.2 innings. The former fourth-round pick who was acquired by the Cubs in the Alfonso Soriano trade a few years ago had seemingly plateaued at the Double-A level due to control issues, but the Cubs look eager to see what he can do at the next level and if he's able to salvage his career with the organization before the Rule 5 Draft this winter.
Honorable Mention: Spencer Patton
While Patton isn't a prospect, he's pitched very well for Iowa this season. The veteran right hander has appeared once with the Cubs already, and in 21 innings he owns a 1.29 ERA and .189 opponent batting average with 34 strikeouts and six saves in six chances.