Spurs Coach Gregg Popovich would find a reason to yell even if his team wasn’t seventh in the Western Conference. (AP Photo/Bahram Mark Sobhani)

CHARLOTTE — Even if Tony Parker wasn’t gradually easing his way back into form a hamstring injury, Kawhi Leonard hadn’t missed 18 games because of injuries to his wrist and eye, Tim Duncan wasn’t playing more minutes than he has in five years, and the Manu Ginobili amusement park ride hadn’t produced a few scream-inducing dips, San Antonio Spurs Coach Gregg Popovich still would find some reason for concern with his team.

“You just deal with whatever you have and move on,” Popovich said recently. “I don’t think there are too many coaches who aren’t concerned about something.”

At least Popovich doesn’t have to add complacency to his list of problems for the reigning NBA champions. The Spurs (26-16) want to win back-to-back titles for the first time with Duncan and Popovich. But they have had to adjust to ever-changing lineups and an increasingly unforgiving Western Conference that has provided fewer opportunities for the aging veterans to rest and punished them with seventh place in the standings while they work out the kinks.

“Nothing seems to be easy for us this year,” Ginobili said.

Popovich has used 23 starting lineups through 42 games this season, which is tied with the woeful New York Knicks for most in the NBA. The Spurs have won three straight but are only two games better than eight-place Phoenix, and 10th-place Oklahoma City is lurking, finally back at .500 for the first time this season with a healthy reigning league MVP Kevin Durant. But the Spurs are fortunate to have just eight back-to-back games the rest of the season, and they won’t have to worry about another taxing month like December, when the Spurs played 18 games in 31 days, with seven back-to-backs.

“That is a little bit much for any team, let alone people like us who are older than dirt. We just have to keep our heads up and when we get healthy we will be a very good team,” said Popovich, who has no plans of changing his maintenance and rest plans for Duncan, Parker and Ginobili. “If we’re not ready at the end of the year and have those three guys, we’re not going anywhere.”

San Antonio needed Duncan to tip in a ridiculous lob pass in an overtime to beat New Orleans on New Year’s Eve just to finish 8-10, which was only the third losing month in Duncan’s 18-year career. The Spurs played a franchise-record five overtime games, losing four — including consecutive triple-overtime defeats against Memphis and Portland — and Duncan averaged 34.6 minutes in December.

“Feeling good actually. Responding well, so far,” Duncan said, when asked about his increased workload. “It’s very different. We don’t have that luxury right now. With our depth over the past couple of years, I’ve had the luxury of sitting out a game here or there, but we’re missing a lot of guys. We’re not playing very well. We’re losing games. It’s not of luxury we have right now.”

Tim Duncan has found fewer opportunities to rest this season. (Rob Carr/Getty Images)

Four months shy of his 39th birthday, Duncan is averaging 30.9 minutes a game, his highest since 2009-10. Popovich has managed to give him five games to rest — which is two more through 42 games than last season — and kept him below 30 minutes in all but two games this month.

“There are no nights off now. There are no nights off ever, but there are really no nights off now. Every team we see in the West is a big-time challenge for us and with us dealing with a lot of injuries, lineup changes and everything else,” Duncan said. “We’re just trying to string some together. We’re trying to find a way to feel good about ourselves and have a rhythm. And find a way to win games right now.”

The Spurs have taken pride in being a plug-and-play team, with the system making it easy to go short stretches without a key player by plugging in any serviceable replacement. But Leonard, the 2014 NBA Finals most valuable player, is the most indispensable Spur with the team going a mediocre 17-17 without him over the past two seasons.

Leonard leads the team in scoring (15.2) and steals (2.0) and is second behind Duncan in rebounds (7.5). He returned Friday from missing 17 of 19 games because of a torn ligament in his right hand and the Spurs reeled off consecutive lopsided wins over Portland and Utah.

The Spurs are 9-9 without Leonard this season and just two of those wins have been by double figures. They are 17-7 with him in the lineup and have recorded eight wins by 10 points or more. With Leonard on the floor, San Antonio outscores teams by 13.4 points per 100 possessions. Without him on the floor, they are outscored by 1.3 points per 100 possessions.

“Without Kawhi, we stink on defense,” Popovich said. “That’s the bottom line. He does all kinds of stuff for us. He guards the best player, he guards different guys, he rebounds the position. He makes steals, he covers for his teammates. He’s huge on D.”

San Antonio has grown to love and embrace all that comes with the improvisational maestro Ginobili, whose up-and-down play has corresponded well with the Spurs’ season. Ginobili has mixed some confounding moments with flashes of brilliance. He made up for combining for nine turnovers in those triple overtime losses by scoring 27 in a close win over Charlotte and 26 in a closer win over the Pelicans.

Kawhi Leonard  makes a difference with his mere presence. (AP Photo/Bahram Mark Sobhani)

The Spurs have had to depend more on his playmaking skills while waiting on Parker to return to his all-star form. Popovich is confident that it won’t take long but losing Parker for an extended time was especially difficult with backup Patty Mills missing 31 games after recovering from surgery to his shoulder and also trying to regain his conditioning and rhythm.

Parker was at his best in late November, when he strung together four consecutive 20-point games during the Spurs’ season-high eight-game winning streak. But Parker has topped 20 points only once since, in a Dec. 22 win over the sixth-place Los Angeles Clippers.

“It has been very frustrating for me this year, because it has been a tricky injury with the hamstring,” Parker said. “I am just going to stay positive, and get back to my normal level to try to help the team win.”

Ginobili said he hasn’t looked at the standings in weeks, with his focus being more on how well the Spurs are playing. When a reporter asked Ginobili about the Spurs being the ultimate team, the Argentine responded that the unit that wowed the basketball world with a dismantling of Miami in the Finals last season has yet to arrive.

“I think last year, for a big part of the year, we were. We played at a really high level. We are still not quite there yet,” he said. “We don’t have everybody at their best as we were in the playoffs and we’re not as sharp. We know we can do it. It’s just not easy and things aren’t going our way.”

Popovich would prefer to be closer to first-place Golden State than being out of the playoffs altogether but doesn’t believe that a true title favorite has emerged aside from possibly the Warriors, “because of their record, I guess,” he said. But he believes the Spurs have plenty of time to get healthy and get it together.

“Winning championships is difficult no matter how you slice it,” he said. You don’t have to have the best record in the league to win a championship. We’ve done both. We have done everything. We have gotten beat in the first round, we’ve been low, we’ve won the whole thing. Every year is a different animal and mosaic, so to speak, and you try to put it together the best you can. Hopefully we have good times to look forward to when we get everybody back.”