Speaking to ESPN's Marc Stein on the TrueHoop Conversations podcast about whether his return for the 2017-18 season can be considered a lock, Nowitzki said: "I think so ... unless something drastic changes here in the next few weeks or the last few weeks of the season, which I don't anticipate.
"I said last summer: I signed a two-year deal, [and] that obviously meant I want to play for two more," Nowitzki continued. "I want to complete that deal."
Nowitzki, who will turn 39 in June, is the league's sixth all-time leading scorer and, after Friday night's 104-100 win over Memphis, sits 38 points shy of joining Kareem Abdul-Jabbar, Karl Malone, Kobe Bryant, Michael Jordan and Wilt Chamberlain on the short list of players to score 30,000 NBA points.
Playing in 2017-18 would give Nowitzki an even 20 seasons in the league with the Mavericks, which would tie Bryant's record run with one franchise.
Bryant retired after the 2015-16 season, his 20th in a row playing for the Los Angeles Lakers. Tim Duncan also retired at season's end after completing 19 consecutive campaigns with the San Antonio Spurs.
"Twenty is a great number," Nowitzki told Stein. "I think 20 seasons also with one team, like I'm trying to do it -- I think only Kobe has done it -- that's another great accomplishment. So I kinda want to make the 20 fold. Plus that summer I'm turning 40. I think that's also a good number to be in the league ... from 20 to 40. That's what I'm looking at.
"'Hopefully I'll finish this season out strong, and then have a decent year, hopefully not as [many] injuries next year."
Nowitzki played just six of Dallas' first 29 games this season because of an Achilles injury that began plaguing him in an overtime loss at Indiana on opening night.
The 2007 MVP and 2011 NBA Finals MVP is earning $25 million this season and is under contract next season on a $25 million team option. It remains to be seen whether Mavericks owner Mark Cuban will simply pick up Nowitzki's full 2017-18 option in June or ask Nowitzki to come to terms on a new deal at a lower salary that helps Dallas create more salary-cap space for free-agent pursuits in July.