The Chicago Cubs need starting pitching and they will look to add an arm before the MLB trade deadline on July 31.

That much is certain.

But who the Cubs acquire — and when they make a move — is still up in the air.

As is the cost — what will Jed Hoyer’s front office have to give up for the starter (or two) they trade for at the deadline?

It could be a hefty price.

MLB Network insider Jon Heyman joined the “Mully and Haugh Show” Monday morning on 670 The Score to discuss the upcoming MLB trade deadline and believes the Cubs will be aggressive.

“I do think Jed Hoyer has done a terrific job,” Heyman said on the show. “He is in the last year of his contract. He does want to win.”

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But the Cubs are far from the only team in search of a starter before the deadline.

“The problem really is the number of good starting pitchers who are going to be available is very, very limited and the numbers of teams that need starting pitching are very, very high,” Heyman said. “… I think that almost every contending team is going to go for a starting pitcher. … The competition is keen, and you’re going to have to overpay to get a Mitch Keller. He may end up being the best starter out there.”

Keller is the Pittsburgh Pirates right-hander who is reportedly being floated out on the trade market.

Heyman discussed several other pitchers who could be available — Milwaukee’s Freddy Peralta, White Sox starter Adrian Houser and Kansas City’s Seth Lugo. But he shot down the potential of Peralta and Lugo being dealt for various reasons and Houser comes with his own question marks.

The veteran right-hander has a 1.60 ERA in eight starts with the White Sox this year but he had -0.7 WAR and a 4.76 ERA in the three seasons prior (2022-24) with the Brewers and Mets.

Teams could still drop out of the playoff race over the next three-and-a-half weeks, which could mean more starters hit the market.

But right now, Heyman thinks it’s shaping up to be a true seller’s market — where the few rebuilding teams have all the power and are expected to drive up the price.

That also means there is no need for a team like the Pirates to jump the market and make a move now. It serves them better to wait and see how high the price can get.

“Mad rush – that’s a good phrase. I think that’s what we’re gonna see,” Heyman said. “I think the prices are probably enormous now. I don’t even have to hear the complaints from the buyers. They’ve got to be enormous because they know how badly these teams need starters and they know that this is a real seller’s market. So I think they’re gonna have to be pressed by a deadline and we’re probably talking the last 48 hours.”