by Marcel Mutoni @ marcel_mutoni 

Dwyane Wade has missed 12 games so far this season, and according to LeBron James, Wade’s absences from the lineup due to gimpy knees have made things increasingly challenging for the Miami Heat.

After admitting to some knee soreness on Monday, Wade sat out his third game in a row last night (a 93-86 win over the visiting Boston Celtics.) The defending back-to-back NBA champs have gone 6-6 without their star shooting guard in the lineup.

Per the Miami Herald:

“It’s tough,” James said. “Guys think it’s easy, but it’s tough. We have a team built on chemistry, built on rhythm. With so many of the guys being in and out, and the concern with D-Wade, it’s been tough on all of us. We’ve got to go in with the mindset sometimes that he’s not playing, as opposed to: Is he playing?”

“What we try to do is not predetermine and have expectations about it,” coach Erik Spoelstra said. “You can’t predict it. You’re going to have some good days and some days where you don’t feel great. We know as long as we stick to the routine, he should get better, quicker and stronger. Now that we’re at home we can get back on the routine of strength training and conditioning.”

“We’ve had a little more guys out than just Dwyane this year,” James said. “From a rhythm standpoint, it’s kind of hurt us. We’re a team that is built on rhythm and chemistry, and we’ve had so many guys out with injuries that it’s kind of hurt our performance. Me watching the film, some of the things we’ve been able to cover in the past is off. Last year, when D-Wade went out, we had Mike Miller to step in. Mike Miller was in the system for a while, so we could automatically fill that void. Now, with D-Wade out, it’s given more opportunities to guys that haven’t been in the system as many years or as many situations as Mike Miller.”

Miami has started a dozen different lineups so far, as Spoelstra sorts through various injuries — only Norris Cole has suited up in every game this season. The Heat went 11-2 with Wade in street clothes last season, and 14-3 in 2011-‘12.

Injuries and fatigue are taking their toll as the Miami Heat go for a third straight title. The task promises only to get more difficult going forward.