There is, sort of. Since I'm focusing on the later innings, I'll ignore how the Brewers have fared against relievers that have gone through the lineup more than once in a game (long-reliever/swingman types). The offense sports a .235/.327/.385 line against relievers, compared to the league average of .243/.318/.381. So in general, the team shows a little more patience and power than league average, but isn't getting as many hits.
But just looking at the 8th and 9th innings, a larger discrepancy emerges. In the 8th inning, the offense's line moves to .222/.313/.361, compared to a .241/.313/.383 league average. The 9th inning is a disaster for the Brewers' bats; .198/.299/.341, well behind the league's .234/.306/.370. Their OPS+ is 94 and 90 for the 8th and 9th innings, respectively.
These findings would not be surprising if the Brewers were a below-average offense. But they're not. They're OPS+ is currently at 101 (100 being league avg.), and they are 13th in runs scored (out of 30 teams). The offense as a whole is ever-so-slightly above average.
What can we glean from this? Probably nothing other than bad luck. Although it's entirely possible that the batting order contains a lot of hitters that are bad at situational hitting (I refuse to consider "clutch" a thing), a lot of it is likely BABIP-related, as a .240 BABIP in the 9th inning is not sustainable. And while poor luck in the later innings isn't the reason the Brewers has underachieved, considering the team's performance in close games overall, it certainly hasn't helped.
Stats courtesy of Baseball Reference