Dodgers’ reliable bullpen bombs in series finale vs. Rockies

The irony of Sunday’s loss to Colorado, in which Dodgers relievers Sergio Romo and Chris Hatcher both gave up crushing home runs, is that the bullpen had kept a pristine ledger through the first three days at Coors Field.

Four games in this city, which resides a mile above sea level and saps the life out of pitchers, is a sizable assignment. The Dodgers managed to avoid disaster until Sunday, when the team’s two least-reliable relievers succumbed to the long ball.

“The bullpen has been great,” manager Dave Roberts said. “This is, obviously, a tough park to pitch in, and a very good lineup. These guys, when called upon, answer the bell.”

The Dodgers relievers entered Sunday’s game with a 2.78 ERA. That is the lowest mark in the National League.

The team faces a decision on its bullpen composition, as both Brandon McCarthy and Rich Hill return to action this week. The Dodgers are currently carrying eight relievers, and may need to move one off the roster to clear at least one opening.

The pitcher most likely to be optioned appears to be Grant Dayton, who has a 4.09 ERA and has been surpassed by Luis Avilan as Roberts’ top left-handed reliever. The team has also shown an affinity for using the 10-day disabled list to shift players around.

McCarthy set to start Monday

McCarthy is slated to start against the Giants on Monday in his first outing since April 29. McCarthy dislocated his nonthrowing shoulder earlier this month, which led to stint on the 10-day disabled list. McCarthy threw a simulated game earlier this week.

“He’s chomping at the bit,” Roberts said. “We expect him to be sharp and go out there and give us a chance to win.”

Hill (blister) is also expected to be activated on Tuesday. Hill has not pitched since April 16.

andy.mccullough@latimes.com

Twitter: @McCulloughTimes