PITTSBURGH — Relentless is the word the Cubs keep using to describe a lineup that knocked out Gerrit Cole on Monday night with the bases loaded and two outs in the fifth inning and the Pittsburgh Pirates already trailing by two runs at PNC Park.

Relentless could also be a label for Theo Epstein’s front office, even after spending almost $290 million on free agents and even with an 18-6 record that’s the best in baseball following a 7-2 win over the Pirates.

The Cubs want nothing to do with the randomness of another elimination game and can’t take anything for granted with 85 percent of the schedule still remaining. They’ve already lost playoff hero Kyle Schwarber for the season, and the outfield picture is clouded with Jason Heyward dealing with a sore right wrist since early April and Matt Szczur scheduled to get an MRI on his right hamstring on Tuesday morning.

Not that Epstein needed a reminder, but the president of baseball operations flashed back to last year’s National League wild-card game when he flew into Pittsburgh, checked into the team’s downtown hotel across the Roberto Clemente Bridge and went running along the Allegheny River.

From his hotel room, Epstein could sort of see where Schwarber’s two-run homer off Cole flew out of PNC Park last October, giving this franchise a runaway sense of momentum.

“We’ve played really well,” Epstein said, “but I don’t think we’ve completely locked in yet or clicked in all facets of the game. Our pitching staff’s really been carrying us. It’s been the most consistent part of our team yet. As it warms up here, I think the bats will get going and they’ll probably carry us for a while.

“But as far as needs that we might have, or ways that we can get better, we’re always assessing that. I think there’s lots of different ways we could potentially improve the club before the end of the season.”

The Cubs will watch Tim Lincecum’s upcoming showcase in Arizona because they always check in on potential impact players at that level. Lincecum — a two-time Cy Young Award winner who helped the San Francisco Giants win three World Series titles — is making a comeback after hip surgery.

While the Cubs should have big-picture concerns about their rotation and a farm system that hasn’t developed the arms yet, Jason Hammel (4-0, 1.24 ERA) is making his own comeback.

Even if manager Joe Maddon doesn’t seem to completely trust Hammel, who gave up two runs across five innings and got pulled after throwing 89 pitches and accidentally hitting Starling Marte to lead off the sixth. Four different relievers combined to shut down the Pirates (15-11) the rest of the night.

Epstein — who is in the fifth and final year of his contract and used “status quo” to describe his extension talks with chairman Tom Ricketts — will have the position-player prospects to bundle if the Cubs do need a frontline pitcher this summer. A franchise-record payroll in the neighborhood of $150 million was also projected to have some room for in-season additions.

After beating up on the division’s have-nots and going 8-1 against the Cincinnati Reds and Milwaukee Brewers, the Cubs should have a better idea of where they stand after Maddon’s “Minimalist Zany” road trip to Pittsburgh and a four-game showdown against the Washington Nationals at Wrigley Field.

“There’s always the threat of somehow playing to the level of your competition in a negative way,” Maddon said. “I’m not denigrating any team that we’ve played to this point. That is not my point. But if you play teams with less-than (.500) records and maybe they’re not playing as well, you don’t turn that dimmer switch up to the full velocity. But when you’re playing really good teams, I think that naturally brings out the best in you.”