MESA, Ariz. — The so-called “edge” of John Lackey. The swagger of Jake Arrieta. They were among the forces from within the clubhouse the last two years credited with driving some of the Cubs’ historic play on the field.

How much did the Cubs lose with the free-agent departures of those starters? How much of that do they still need? And what kind of influence will their new big-money starter, Yu Darvish, bring?

“Hopefully, between 15 and 20 wins,” Cubs manager Joe Maddon said. “That always makes the clubhouse feel good.”

Darvish, the $126 million final piece to the roster, makes his first start of the spring Thursday against the Rockies, offering a glimpse of that 15-to-20-win potential, if not the kind of voice he might bring.

“He goes out there and plays like he’s definitely capable of playing, that’ll speak very loudly,” Maddon said.

Darvish, a four-time All-Star, is known for one of the widest array of pitches — five, six or even seven, depending on how you count them or who you talk to — in the game, and he can throw each pitch effectively.

He throws a mid-90s fastball, and he has proved over the last 1½ seasons that he’s back to full strength after Tommy John surgery.

“We’ve all seen his stuff. It adds a confidence boost,” Cubs left-hander Mike Montgomery said. “It makes other teams look at us with a little more respect. It gives us that confidence we’re going to go out there and win every game. You know that’s not going to happen, but that’s what our mindset is.”

How does he fit into the tightly knit clubhouse? How does he interact? What’s his personality?

From the outside looking in, he seems quiet and task-minded, busy and almost always headed to the next thing on mornings before practice.

“He’s kind of got this real quiet, good sense of humor,” Maddon said. “I think he takes a lot in. He’s very observant. Interaction-wise, it’s been very comfortable.”

The Cubs’ front office prides itself on the human side of its analysis of players, how they mesh with teammates and how they conduct themselves away from the field.

“One of the things we love about him at this moment in time is we think he’s not gotten to the point with his mental abilities and focus and his maturity to match his physical abilities,” team president Theo Epstein said when the Cubs announced the signing. “We think he’s at a real nice point in his career.”

That wasn’t always the perception, especially early in his career with the Rangers.

Chris Gimenez, a teammate with the Rangers then and the Cubs now, suggested Darvish was uncomfortable with his “rock star” status and all the attention he got after signing his first American contract.

“I think at the beginning, he didn’t really communicate with guys,” said Gimenez, who said that began to change with Rangers teammates joking and “messing” with him. “And he kind of opened up a little bit.”

One thing Gimenez discovered about Darvish: “He’s sneaky funny.”

He has shown some of that just in the last several months. During a postseason news conference last fall, he was asked about all the changes the Dodgers had asked him to make to his mechanics — and whether there was anything they did not ask him to change.

“They told me, ‘Hey, you should not change your good-looking face,’ ” he said.

And when someone asked him during his first Cubs news conference if he liked having his old catcher and friend Gimenez on the team, Darvish said, “I like [Willson] Contreras better.”

“I just think getting his personality out there is a big part of it,” Gimenez said. “You want guys to feel free and loose, and then you get the best out of guys.

“This is a great fit for him because he can kind of just be who he is and doesn’t have to be somebody who he doesn’t feel he is.”

Follow me on Twitter @GDubCub.

Email: gwittenmyer@suntimes.com