The Cubs starting rotation ranks first in all of baseball with an ERA of 3.09. The Nationals rank second with an ERA of 3.39, a full three-tenths of a point behind the Cubs. So, you may ask yourself, why would the Cubs need another starter? Since June 13th, the Cubs rank 20th with an ERA of 4.83, while sitting just above the Reds with a starting rotation fWAR of 0.2, good for 29th in baseball.
Part of the reason for the rotation's recent struggles can be attributed to a mediocre month's worth of starts from Jake Arrieta and Jon Lester. In their last five starts, Arrieta has compiled an ERA of 5.27, while Lester's is even worse at 6.84. There is room for optimism, however, as Lester posted an ERA of 3.04 after the All Star break last year, and Jake Arrieta had the best second half in the history of baseball. I am confident Arrieta and Lester will both find their stride after the break, leading one of the best rotations in baseball.
There is one pitcher in the rotation that Cubs fans can reasonably expect to decline from his hot start, that starter is Jason Hammel. In his first two months of the season, Hammel recorded an ERA of 2.09, which was good for one of the best ERAs in baseball. Since then, Hammel has compiled an ERA of 5.36, which has raised his ERA to 3.46. Hammel's recent struggles aren't the only call for concern.
As mentioned above, Hammel sports an ERA of 3.46; however, he has a FIP of 4.55, meaning that his ERA is better than what it should be. The second statistic that is alarming is Hammel's BABIP. Hammel owns a BABIP of .245 this season, far below his career norm of .300. Hammel's FIP and BABIP are solid indicators that he's due for regression. Those stats, paired with the fact that Hammel is notoriously bad in the second half (he posted an ERA of 5.10 after last year's All Star break), mean that the Cubs could be shopping for a starting pitcher.
Proposal #1: A's trade LHP Rich Hill to the Cubs in exchange for OF Eloy Jimenez and LHP Bryan Hudson
This year's top rental arms consists of Rich Hill, Jeremy Hellickson, and Andrew Cashner. Since Hill is in a tier of his own with the other rentals, he is going to be in extremely high demand. So high in demand in fact, that I don't think the Cubs make a run at him. If the Cubs do decide to pursue Hill, the A's will have a ton of leverage due to his popularity, and will surely look to acquire one of the Cubs' top three prospects. Hill has been excellent this year, posting an ERA of 2.06, while striking out more than a batter an inning. Adding Hill to the rotation would move Hammel to the bullpen, creating an impressive 1-2-3 consisting of Arrieta, Lester, and Hill. The A's would look to add Jimenez to a farm system that is deep in infielders and pitchers, but is seriously lacking in outfielders. Jimenez could potentially start in RF for the A's within a few years, giving them an athletic, middle of the order bat with decent fielding skills. Drafted in the third round last year, Hudson has plenty of potential as a 6'8" lefty, and profiles as a back end of the rotation starter.
Proposal #2: Padres trade LHP Drew Pomeranz to the Cubs in exchange for 2B/OF Ian Happ, RHP Dylan Cease, and OF Donnie Dewees
Having been traded to the Rockies in the blockbuster deal that sent Ubaldo Jimenez to the Indians, Pomeranz got off to a terrible start to his career, recording an ERA of 5.20 in his three years wearing a Rockies uniform. Once Pomeranz left the launching pad that is Coors Field, he started to look like the former 5th overall pick taken out of Ole Miss. Pomeranz posted an ERA of 2.47 heading into the All Star break, and like Hill, is striking out more than a batter per inning. Pomeranz comes with significant control as well, as he's due to become a free agent in 2019. Similar to Hill, Pomeranz will be a hot commodity in the next few weeks, since as many as 10 teams are said to be interested in him. Ian Happ, who was just recently rated as the 37th best prospect in baseball according to Baseball America, would be the headliner in a deal involving Pomeranz. Happ's versatility allows him to play primarily 2B and LF, however, Happ's value as a 2B is why he was just rated so highly. Happ's 20-20 potential would play well in Petco Park, while Happ should be ready to contribute to a Major League roster as early as next year. Cease wouldn't be a throw-in for this deal, as an argument can be made that Cease is the Cubs top pitching prospect at the moment. Cease has electrifying stuff, but while the potential is there, he's a long ways away from the majors, having only reached Eugene. Dewees, taken in the 2nd round of last year's draft, is a speedy CF who has already hit 11 triples this year to go along with 16 steals, would be a good third piece for the Padres to add in a deal involving Pomeranz.
Proposal #3 Rays trade Jake Odorizzi to the Cubs in exchange for SS Gleyber Torres and 1B Dan Vogelbach
Odorizzi was rumored to be on the Cubs radar in the offseason, and while he hasn't pitched as well as he did last year, he will still command a considerable package due to the fact that he is controlled for three more years. Odorizzi owns an ERA of 4.47, but that can partly be attributed to playing in the hitter friendly AL East. Odorizzi has already given up 17 HRs, as he only surrendered 18 last year. Odorizzi's HR/FB ratio of 13.1% is uncharacteristically high for him, as his career average 9.7%, so Cubs fans could potentially expect that number to decline as the season progresses. When the Cubs and Rays were discussing Odorizzi, the Rays reportedly asked for one of Javier Baez or Jorge Soler. Instead of adding Baez who has since increased his value, or Soler who has probably decreased in value, the Rays would most likely ask for Gleyber Torres in a deal involving Odorizzi. After getting off to a poor start in Myrtle Beach, Torres has pulled his slash line up to .270/.348/.423 while showing power as he's already hit nine HRs, more than his last two seasons combined. If Torres can stick at SS, he has the potential to be a top 10 SS in the majors as he could posses an above average bat, defensive skills, and speed. Dan Vogelbach would be a solid piece for the Rays to acquire in a trade for Odorizzi, as he posses plus power and plus on-base skills. Vogelbach has had his best season as a professional, hitting .312/.426/.547 with 15 HRs. I'll go on the record as not loving Odorizzi as a potential trade target as he has a career GB% of only 34.5%, making him particularly susceptible to HRs if the wind is blowing out at Wrigley.
Proposal #4 Braves trade Julio Teheran to the Cubs in exchange for INF Javier Baez and RHP Jen-Ho Tseng
Teheran has been the one bright spot on a horrendous Braves team this year. Heading into the break, Teheran owns an ERA of 2.96. Teheran's improvement from last year can be attributed to a substantial decrease in his BB/9 and WHIP. Teheran's WHIP sits at 0.969, which ranks 4th in baseball, only behind Clayton Kershaw, Max Scherzer, and Madison Bumgarner. Teheran is owed just over $25 million over the next three years, with an option for a fourth year. This type of cost effective control, particularly for someone who has already been worth 3.2 bWAR, will not come cheap. Enter Javier Baez. Baez is on pace to hit more than 15 HRs this year, while playing elite defense at three positions (2B, SS, and 3B). Baez still has plenty of room to grow, as he has the potential to hit 30+ HRs, while providing elite defense at SS. That potential is what the Braves would have to be sold on, as he would be the centerpiece of a deal involving Teheran. Tseng is having a good year at AA, owning a record of 5-3 with an ERA of 3.34. Still only 21, Tseng has the potential to become a back of the rotation starter.
Not Included: Chris Archer (Rays) and Sonny Gray (A's). In Archer's case, I don't think the Rays sell low on one of the best young pitchers in the game. In regards to Sonny Gray, his poor performance this year, along with his DL stint will keep teams from meeting the asking point Billy Beane will have.