Celtics guard Brad Wanamaker scored 10 points and had six assists in Boston’s 99-85 win at Phoenix on Monday night. Matt York/Associated Press

PHOENIX — When Brad Wanamaker weighed his options as a free agent this summer, he spoke to Boston Celtics Coach Brad Stevens about the opportunity he could have if he returned to play for the Celtics again this year.

The discussion didn’t include any guarantees. Stevens clearly liked the veteran point guard, and on a team full of youngsters, the 30-year-old would be the oldest player. But still, Wanamaker’s takeaway from Stevens was that he would have to earn any minutes he received.

No problem.

“That’s how it’s been my whole life,” Wanamaker said. “I’ve never had anything handed to me. I kind of like that approach. Keeps you hungry, keeps you wanting more.”

Fast forward a few months. Wanamaker had just poured in 10 points and dished out six assists in Boston’s 99-85 win over the Phoenix Suns Monday night – an important win on the second night of a back-to-back that got the Celtics back on track after a tough loss to the Kings.

Stevens was asked how important Wanamaker’s contributions have been to the Celtics (11-2), and he raised his eyebrows.

“Like, huge,” Stevens said. “I mean, one of the more important things on our team, because you know what you’re getting every day. And he’s been really good. You can play with him with the ball, he can play off of it, he can guard bigger guys because he’s strong, and he’s very smart. So he makes the other players around him better when he’s in the game. You kind of see he’s doing some of the things that we would normally ask Gordon (Hayward) to do when he’s in with that group, and he’s doing a great job. He’s real steady right now.”

Stevens is right: One of the more under-discussed aspects of Wanamaker’s play has been the way he filled in for Hayward since the Celtics’ star broke his hand against the San Antonio Spurs – posting 9.4 points and 3.8 assists in the last five games. The Celtics weren’t as concerned about replacing Hayward’s points as they were his play-making. Hayward was a strong secondary playmaker who could carve up and collapse defenses.

Now Wanamaker has shouldered much of that load, and he shouldered even more of it when Marcus Smart went down with an ankle injury in the fourth quarter of Monday’s win.

“Obviously Smarty is a special player for this team,” Wanamaker said. “Both ends of the floor, he’s making plays. So when he goes down, just try to stay within the offense, but also be a little more aggressive.”

Wanamaker can run the pick-and-roll reliably, and he’s a threat both from 3 and around the rim with a variety of layups and floaters. As Stevens noted, his strength makes him versatile defensively.

But maybe more important has been Wanamaker’s leadership.

“He’s an older guy who has been playing basketball for a long time,” Jayson Tatum said. “He brings a certain poise and understanding of the game. He really is like a true point guard out there. Slows things down.”

This year’s Celtics’ roster is full of nontraditional veterans. Kemba Walker is the team’s star, but he joined the team this summer. Marcus Smart feels like a veteran, but he’s just 25. Hayward is a reserved personality. And while Wanamaker is the only 30-year-old on the team for a few more months, his NBA career started last year.

Still, having an older voice can be useful.

“I help out when I can,” Wanamaker said. “I try to voice my opinion, just on the strength that I’ve been playing basketball for a long time. But everybody with this team, this year especially, everybody has a voice. It’s pretty cool that everybody’s speaking up, even the rookies at times, they talk to us at times. Just that trust in each other, everybody giving each other advice.”

Asked if everybody having a voice this year is different than last year, Wanamaker said, “Nah,” and repeated it seven times (a real veteran move). As last year progressed, Wanamaker never expressed any disappointment in his lack of minutes, but sitting – especially while the team struggles – is endlessly frustrating.

“There was just no chance for it to go the way he wanted it to last year,” Stevens said. “Any time you had a guy out, it was more time for everybody else that was in our top seven or eight. And as much as you know that coming in or you’re aware of that coming in, that’s just hard to stomach in the middle of it as you’re going through the 82 games. … There’s also going to be days where he doesn’t play as much, but he’s a pro and he comes to work.”

This year, Wanamaker is doing everything he can to maximize his opportunities. Stevens praised the example Wanamaker sets, saying he never misses a voluntary day, even if he’s only working with rookies.

“Just go out there and produce every chance I get,” Wanamaker said. “That’s the biggest key. I mean, you see we deep. Last night Semi (Ojeleye) stepped up big for us. Grant (Williams) came in today making plays. You never know when your number is going to be called. So you have to be ready.”