"We're way behind those guys," LeBron James said following the Heat's practice on Wednesday. "Just look at the number of games played, the number of playoff series those guys have had. We're only a few months in together -- 40-something-plus games. I've seen the statistics.
Boston has like 250-plus games played together. We're way behind those teams."
The Heat, who acquired James and Chris Bosh in July to join Dwyane Wade in Miami, have played only 48 games together with that core of stars. In contrast, the Celtics' primary starters, a cast that includes Kevin Garnett, Paul Pierce, Ray Allen and Rajon Rondo, were assembled in 2007. Other title contenders feature rosters of familiar faces, as well.
"You talk about Boston, you talk about Orlando or the Lakers, we're never going to catch those guys in experience," Dwyane Wade said. "I think the stat is, Boston is 30-15 in the playoffs since they've been together. We're 0-0."
That Celtics starting unit is actually 30-17 during its three playoff runs, but Wade had the Heat's 0-0 record correct.
Heat coach Erik Spoelstra has stressed all season the importance of developing a common familiarity -- particularly among the Heat's primary scorers -- through meticulous preparation and the repetition that comes with the grind of the NBA season.
"The No. 1 thing is time," Spoelstra said. "We need time on the court. We need to take advantage of practice days like today, shootarounds, because there are some lineups we're playing right now that literally had not played together after 47 games."
The Heat are gradually working swingman Mike Miller into lineups alongside James, Wade and Bosh. The four-man unit played together for the first time on Sunday in Oklahoma City, to positive results. Miller missed the first two months of the season with a thumb injury. With his return, the Heat now have their four most prolific scorers healthy.
"The biggest thing for us, the Miami Heat, is we want to keep everyone healthy," Wade said. "The more time we can get together, whether it's practice sessions, whether it's film sessions, whether it's in a game, is going to be positive for us."
Kevin Arnovitz covers the NBA for ESPN.com.