With their 116-101 win over New Jersey on Tuesday at Philips Arena, the Atlanta Hawks are now 4-1 without their most expensive player, two-time All-Star guard Joe Johnson.

While this is great news for the Hawks — it was unclear how they would fare without Johnson, who has been out since Dec. 1 and will miss the next 4-6 weeks while recovering from elbow surgery — and their regular season prospects, it’s also a sobering reminder of just how bad a contract Johnson was given this offseason.

On July 8, Johnson re-signed with the Hawks for a max contract of six years, $124 million, which crippled the team’s salary cap flexibility in the long term and essentially ended any chances of them acquiring a significant player through free agency or a trade the next six years.

That alone is enough to make the deal one of the worst in NBA history.

Then there’s the realization he’ll be in his mid-30s — he turns 30 this offseason — making $20 million a season toward the end of his contract, which makes him virtually impossible to trade. But what’s worse — the Hawks are proving they can win without him.

The current starting lineup of Mike Bibby, Marvin Williams, Josh Smith, Jason Collins and Al Horford is 2-0, and that includes an 80-74 victory Monday over the Magic in Orlando. For some perspective, the Hawks — with a healthy Johnson — hadn’t previously won in Orlando since Oct. 29, 2008.

Are the Hawks an even better team without Johnson? For Atlanta GM Rick Sund’s sake, they better not be. The next month or so until Johnson returns could make an argument they are.

One thing is for sure: the Hawks surely aren’t missing him right now.

And in this month Johnson is out, the Hawks will get acclimated to playing without him. They’ll form a new chemistry, one that could have them playing at a high level. What happens when Johnson returns? Will coach Larry Drew and the Hawks have to go back to the drawing board to find a way to re-acquaint them with the team?

That’s a scary prospect.

A look at the bigger picture: the Hawks have never advanced past the second round of the playoffs since they came to Atlanta in 1968. They’ve been to the playoffs the last three seasons — all with a healthy Johnson. And Atlanta depended on Johnson to elevate the team to at least the conference finals, but instead he’s earned the reputation of not being a clutch player in the postseason. In the past three seasons, Johnson has averaged 21.4 points a game in the regular season, but only 18.1 in the playoffs.

Dwyane Wade and Lebron James — both of whom took less money than Johnson when they signed with the Heat this offseason — have career playoff scoring averages higher than those of their regular season averages. But Johnson has proven he’s not as good as either — Wade averaged 33.8 points in the 2006 Finals and was named Finals MVP and James led the Cavaliers to their only Finals appearance in 2007.

The Hawks are stuck with Johnson. At the moment, they’re stuck with him on the bench. As for this season, sure, they have a shot at a No. 4 or 5 seed, but not much of a chance at advancing past the second round.

They’ve proven, with this unit, they’re not built to compete with the Celtics, Magic and now possibly the Heat — Miami represents Atlanta’s only Johnson-less loss, an 89-77 defeat last Saturday — in the postseason. While the Celtics are fading with age, the Heat and Magic aren’t.

That’s why the Hawks needed flexibility to upgrade the team. Instead, they’ll likely part ways with Jamal Crawford, an integral bench piece named 2010 NBA Sixth Man of the Year. Crawford, making $10 million in the final year of his contract, will be an unrestricted free agent after the season and another team could easily outbid Atlanta for his services. Even worse, Johnson’s contract could result in the eventual trade of the 25-year-old rising star Smith, who signed a five-year, $58-million extension in 2008.

Even before the Hawks lost Johnson to injury, it was obvious his contract was a bad move. Atlanta’s 4-1 start without him is just reinforcement of that notion.

Adam Krohn is a sports writer for The Times. Follow him at twitter.com/gtimesakrohn.