Things obviously turned out much differently.
More than two months after All-Star guard Williams opted to stay with the Nets for their move to Brooklyn rather than come home to play, the Mavericks formally introduced the five veteran players they were able to add instead.
''We went on the option for the big free agent. That didn't work out. Honestly, that wasn't my first choice,'' owner Mark Cuban said Monday. ''Sometimes the best deals are the ones you don't do and they lead to better things. And I think that's what happened now.''
Dallas got Elton Brand on a waiver claim from Philadelphia, signed free agents Chris Kaman and O.J. Mayo, and acquired Darren Collison and Dahntay Jones in a trade from Indiana. All those moves were made in July.
The newcomers sat with Cuban and coach Rick Carlisle at a long table set up on a podium on the main floor of the team's home arena.
Season ticket holders were invited to attend, and a couple of hundred of them sat in the stands munching on free popcorn. A few even got to ask questions during the hour-long session, which came just less than three weeks before the start of training camp Sept. 29.
Add the three rookies drafted in June, and the Mavericks' current 15-player roster has only seven players back from last season. Only four players remain from their NBA title team the year before that, including perennial All-Star Dirk Nowitzki, who is going into his 14th season.
''Definitely, we want to keep Dirk's window open as long as possible to win another championship,'' Brand said. ''We're hungry because we don't have championships and he does. Hopefully, we make just job a lot easier.''
Philadelphia used its one-time amnesty provision in the new CBA to let Brand go, and the Mavs won the waiver claim. The 33-year-old two-time All-Star who will make $18.1 million the final season of a five-year contract that will be paid mostly by the 76ers.
''I've still got a lot left in the tank,'' Brand said. ''I feel great.''
Kaman, a 7-foot center, spent last season in New Orleans after eight years with the Los Angeles Clippers, spending five of those with Brand. Kaman has also been on the German national team with Nowitzki.
Mayo played the first four seasons of his career in Memphis, averaging 15.2 points in 301 games. The 6-foot-4 guard has already been in Dallas about a month acclimating himself to the organization and the area.
''It's going to be fun,'' said Mayo, the former USC star who was the third overall pick in the 2008 draft.
''I think he can be a star,'' Cuban said. ''I think O.J. knows this is his make-or-break who am I going to really be in this league. Coach is going to him that opportunity.''
Dallas sent Ian Mahinmi to the Pacers in July to get Collison, the guard is going into his fourth season, and Jones, a guard-forward who has played for four different teams in his nine seasons.
Jason Kidd, their 39-year-old point guard whose 1,315 career regular-season games are more than any other active player, and Jason Terry were among the free agents that left Dallas this summer after the Mavericks had the league's oldest team last season.
Before Cuban and the players took the stage, showing on the huge screen above the floor was the ABC-TV broadcast of the Mavericks' NBA Finals-clinching victory at Miami in June 2011.
There wasn't much to show from the last season, such as the season-opening Christmas Day loss at home to the Heat or the playoffs, when the Mavs were swept by Oklahoma City in the first round. The last game was in the same building four month ago, when Dallas blew a 13-point lead in the final 10 minutes.
After their 2011 championship came the NBA lockout and a new collective bargaining agreement with different rules that affected how the Mavs put together their roster. Cuban strategically let go of some big pieces, moves that also created some salary-cap flexibility for the pursuit of Williams that didn't work out as planned.
''We were talking a calculated risk, you guys knew what I was trying to do up front,'' Cuban said. ''I told you there would be a lot of pieces that fell through the cracks because of the way teams were doing their financing now, and told you teams were going to make enormous mistakes because they didn't understand all the nuances (of the CBA) ... and I think a lot of those fell to our favor.''