DALLAS -- Rajon Rondo will be no rental for the Dallas Mavericks after they acquired the four-time All-Star point guard in a blockbuster trade with the Boston Celtics.

The Mavs are “as confident as we can be” that they will sign Rondo to a long-term deal when his contract expires in the summer of 2015, a high-ranking team source told ESPNDallas.com.

If the Mavs didn’t make this type of trade, upgrading the point guard position would have been their top priority next summer, when Rondo and Goran Dragic can test the market. By acquiring Rondo now, it makes it much less complicated for the Mavs to keep what they believe is a championship core intact.

The Mavs own Bird rights on Rondo and center Tyson Chandler, who ended up being a one-year rental for Dallas’ 2010-11 title team. He returned to Dallas in a June trade with the New York Knicks, allowing the Mavs to exceed the cap to re-sign both players. They would own early Bird rights on Monta Ellis if he opts out of the final season of his three-year, $25 million contract, meaning they can sign their leading scorer to a deal starting with a salary up to 175 percent of the $8.36 million he is making this season.

The Mavs’ cap space next summer would have depended on several factors, most importantly whether Ellis decided to take his well-deserved raise now or to wait a year for the projected spike of the salary cap to occur.

It could have been difficult for Dallas to successfully recruit a premier point guard and pay Chandler market value. The Dallas decision-makers do not anticipate having that problem now that Rondo is already on the roster, with the assumption he’ll mesh well with the Mavs and want to continue playing for a contender with a proven championship culture.

The Mavs already have starting forwards Dirk Nowitzki, whose hometown-discount deal made much of the roster remodeling since last season possible, and Chandler Parsons locked up at least through next season. Sixth man Devin Harris, whose deal has two more fully guaranteed seasons, is another core piece locked into a contract with the Mavs.

This isn’t like 2011, when owner Mark Cuban opted for cap space over keeping the aging core of a title team together. The Mavs firmly believe they have a core capable of contending for the next few years with the 28-year-old Rondo, 29-year-old Ellis and 26-year-old Parsons in their prime.

Cuban plans to pay to keep this core together. Dealing for Rondo makes that process much less difficult.