Three games. All three on the road. Three division leaders. That’s what lies ahead for the Mavericks starting Thursday night in Beantown.

“It’s a tough test for us no matter who we’re playing,” coach Avery Johnson said Wednesday before the team departed for Boston. “They’re all terrific teams.”

The Celtics lead the Atlantic, Detroit (Sunday) paces the Central and Orlando (Monday) tops the Southeast. It’s the best of the Eastern Conference for one of the West’s best.  Dallas (31-13) has won four straight and sits second in the Southwest Division behind streaking New Orleans. 

The Mavs have beaten Detroit and Orlando this year, both at home. Dallas is just 11-10 on the road, including 4-5 at East teams, and 10-7 overall against the other conference. Johnson’s troops have won five of the last seven outside of Dallas.

“We look at the stretch we’re going into and we know we haven’t played well on the road,” Jason Terry said, “so this is a chance for us to build up some momentum, build up some confidence, so we’ll see. It’s against good teams.”

Explaining the relative struggles away from home, Johnson listed a couple reasons: Many teams are simply better this season, especially at home, and the Mavs often lose their identity outside of American Airlines Center.

“We’ve tended to be more of a jump-shooting team on the road,” he said. “Our offense has as much to do with our defense as our defense itself. We tend to be less aggressive.

“We’ve seemed to play a little bit better here recently on the road because we’re much more aggressive, much more alert, we attack the basket more and we defend the paint better.”

Boston promises to be a sizable challenge, especially with Devin Harris and Jerry Stackhouse out. Stackhouse (strained right hamstring) did make the trip and has circled Orlando as his possible return. Harris (left ankle bone bruise) remained in Dallas and is likely out until the All-Star break.

After wallowing in mediocrity for years, the C’s are relevant again. The arrival of Kevin Garnett and Ray Allen to team with Paul Pierce has New England dreaming of baseball-football-basketball three-peat. The Red Sox won the World Series, the undefeated Patriots are in the Super Bowl and the Celtics own the NBA’s best record.

“If we play our style of basketball, we feel we can give ourselves a chance to win against anybody,” Johnson said.

The Mavs have won the last seven in the Boston series, but that was against those Celtics. The three-headed Green Monster of these Celtics is a matchup nightmare. Garnett, Allen and Pierce each score 18-20 points per game, but they’ve also got support.

“They’re scoring and playing together and really sharing the ball well,” said Dirk Nowitzki, who has four double-doubles in the last five games. “When they’re on, they’re fun to watch, and they’re sharing the ball and they really put their egos to the side.

“That’s what you’ve got to do when you have great players playing together. They’re fun to watch, but our focus is more on the Western Conference, everything is so tight around here.”

Though no one other than Garnett, Pierce and Allen averages in double figures, the roster is surprisingly deep. In addition to the Big Three, six other Celtics have scored at least 20 in at least one game this season. (Seven Mavs total have done the same.) Since routs are common, Boston coach Doc Rivers has 10 guys averaging at least 9.9 minutes.

Where everyone knows your name

JJ Barea is not only backing up starting point guard Jason Terry, he’s also a mini-celebrity in Boston. (That’s not a reference to his height.) The Northeastern graduate will have his own cheering section at the game.

“They’re going to come back out,” Barea said, referring the rowdy group that’s followed him since his college days. “Not as much as last year, but they’re going to still come out.”

Barea won’t have much time to look into the stands. His focus: Keep the offense clicking and be a pest defensively. Avery Johnson has taken extra time lately to work with Barea as the Mavs navigate the waters without Devin Harris.

“It’s an opportunity for me,” Barea said. “I’ve got to come out and take advantage of it and do whatever I can do for the team.”