By Bruce Levine–

CHICAGO (CBS) — Just less than one-fifth of the way into the season, the NL Central remains bunched up, with the top four teams within a game of one another as of late Sunday afternoon.

For all the talk that might happen about offense, pitching will likely be the difference in who will be the division winner at year’s end. That was the strength of the 2016 Cubs, who boasted a rotation that had an MLB-best 2.96 ERA.

It’s been a different story in 2017, as the Cubs’ rotation — of Jon Lester, Jake Arrieta, John Lackey, Brett Anderson and Kyle Hendricks — carries a 4.79 ERA into Sunday night’s matchup against the Yankees. That ranks 25th in baseball, and Chicago has allowed 40 runs in the first innings, the most in the game.

Much has been made of the Cubs (16-14) rallying for 10 come-from-behind wins this season, but that pressure has been on the offense often because the pitching has struggled. Each Cubs starter has worse numbers than in 2016, and no one is averaging six innings per start. The end result has been a big burden on the bullpen, as six Cubs relievers are on pace to throw in 75 or more games.

“The biggest thing for me is to get our starters deeper into games,” manager Joe Maddon said. “Our bullpen numbers are easily the best by numbers in the National League on a lot of different fronts. They have been pitching too often. Really to make this right, we must get our starting pitching straightened out. If you remember last year at this time, the bullpen had not pitched a whole lot. That is what kept them strong all season. We did not have the emphasis to score a lot of runs because the starting pitching was so good.”

The Cubs bullpen has been overworked in large part because of  recent struggles by Anderson, who has gone only a combined 1 2/3 innings in his past two outings. The end result was a series of roster moves that necessitated designating outfielder Matt Szczur for assignment and making multiple bullpen moves over this weekend.

Anderson is now headed for the disabled list with a back problem, and a new starter will be needed. The good news is the Cubs have two off days in the next eight days after having a busy schedule.

“I really see this thing working its way through,” Maddon said. “Stuff-wise, they all look about the same. Kyle might be down a tick with his velocity. Watching Lackey, he looks the same. Lester overall has been throwing the ball really well. I am not seeing a dramatic change in them from last year. I really am not. I am pretty patient. They just need to get on a couple of good starts in a row. Then it will morph into what it is supposed to look like.”

Bruce Levine covers the Cubs and White Sox for 670 The Score and Follow him on Twitter @MLBBruceLevine.

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