With the 2021-22 NBA season starting next Tuesday, we could see some last-minute trade activity as teams finalize their rosters.

Ben Simmons remains the most likely star to be moved, as he continues to hold out from the Philadelphia 76ers. It's also worth watching how the Kyrie Irving situation unfolds in Brooklyn since the star point guard currently isn't allowed to play in home games.

Some Western Conference semi-contenders such as the Dallas Mavericks and Golden State Warriors should be looking for more veteran talent, especially with co-stars (Kristaps Porzingis and Klay Thompson) who have struggled with injuries over the past few years.

The following four trade ideas don't involve any free agents who were signed over the summer. All four would be allowed to happen before the season begins.

Christian Wood to Dallas, Kristaps Porzingis to Washington in 3-Teamer

Dallas Mavericks Receive: F/C Christian Wood, G/F Eric Gordon, PF Davis Bertans

Washington Wizards Receive: PF Kristaps Porzingis

Houston Rockets Receive: SG Josh Green, C Moses Brown, F Kyle Kuzma, F/C Maxi Kleber, 2025 first-round pick (lottery-protected, via Dallas Mavericks)

The Luka Doncic-Kristaps Porzingis pairing has yet to win a playoff series, which should lead Mavericks general manager Nico Harrison to look for upgrades whenever and wherever possible.

Wood would be a far better fit next to Doncic. He's a more dynamic offensive player who can score from inside and out, doesn't carry the same injury baggage as Porzingis and is on a terrific two-year, $28 million contract.

At age 26, Wood doesn't fit the timeline of the Rockets' rebuild. But he could help Dallas win right away after averaging 21.0 points, 9.6 rebounds and 1.2 blocks while shooting 37.4 percent from deep last season.

Gordon (17.8 points) and Bertans (11.5 points, 39.5 percent from three) would give the Mavericks two additional rotation pieces who can spread the floor and take some of the scoring load off Doncic.

The Wizards would run a small risk by taking on Porzingis, but giving up only Bertans and Kuzma for the 7'3" former All-Star would be well worth it.

Porzingis would give Bradley Beal and Spencer Dinwiddie a huge post presence to play off at either power forward or center. While his contract isn't ideal (three years, $101.5 million), the Wizards would dump their own worst deal (Bertans' three years and $49 million) in this trade.

Wood is set to become an unrestricted free agent before Houston is ready to compete. Moving him now for young talent and draft picks would only help the rebuild and give promising rookie Alperen Sengun more playing time.

Dallas selected Green, 20, with the 18th overall pick in the 2020 draft. Brown, 21, averaged 9.6 points, 10.4 rebounds and 1.2 blocks in 32 starts with the Oklahoma City Thunder last season. Houston would also up another future first-rounder to add to its collection, while Kleber and Kuzma could both play rotation minutes now and be moved for more additional assets at the deadline if needed.

The Rockets would also get to dump the remainder of Gordon's contract (two years, $37.8 million), freeing up more minutes for some of their young talent on the wing.

Nets Trade Kyrie Irving to Spurs

San Antonio Spurs Receive: PG Kyrie Irving

Brooklyn Nets Receive: PG Dejounte Murray, F/C Thaddeus Young, 2023 first-round pick (top-10 protected)

Would Irving really retire if the Brooklyn Nets trade him? Any team interested in acquiring him would need to find out before it pulls the trigger on a trade.

Irving isn't currently eligible to play in home games. Being without him for half the season would be a huge blow for Brooklyn's championship chances.

Murray isn't nearly as talented as Irving, but he is a far better defender who can shut down opponents at the point of the attack. He averaged 15.7 points, 7.1 rebounds, 5.4 assists and 1.5 steals with the Spurs last season.

Since they already have Kevin Durant and James Harden, the Nets don't necessarily need Irving's scoring to win a title. Murray would be a good replacement who makes them better defensively.

Young can play both power forward and center and is a good defender and willing ball mover who can spread the floor. Getting a future first-round pick would give the Nets an additional trade asset for future deals.

For the Spurs, this trade would only happen if head coach Gregg Popovich could convince Irving to come play for him. If he'd be willing to do so, he'd be the Spurs' best player since they traded Kawhi Leonard in 2018.

Despite playing next to Durant and Harden last season, Irving still averaged 26.9 points, 6.0 assists, 4.8 rebound and 1.4 steals while shooting 50.6 percent overall, 40.2 percent from three and 92.2 percent from the free-throw line.

Brooklyn needs to seriously consider whether having Irving for only half of the season is better than taking on a less talented point guard who's available every day.

Warriors Get Win-Now Help, Raptors Build for Future

Golden State Warriors Receive: SF OG Anunoby, PG Goran Dragic, C Chris Boucher

Toronto Raptors Receive: C James Wiseman, SF Andrew Wiggins, 2022 first-round pick (unprotected)

If the Warriors fail to pry Pascal Siakam away from Toronto, Anunoby would be a nice consolation prize.

The 24-year-old wing is quickly becoming one of the best defensive players in the NBA, and he averaged a career-high 15.9 points, 5.5 rebounds, 2.2 assists and 1.5 steals last season while shooting 39.8 percent from deep. He still has plenty of room to grow, and unlike the rest of the youth on Golden State's roster, he already has 21 games of playoff experience and a championship on his resume.

Dragic could start next to Stephen Curry in the Warriors' backcourt until Klay Thompson returns, and he would later slide into a sixth-man role in preparation for a deep playoff run. Boucher is a better win-now option than Wiseman, as he averaged 13.6 points, 6.7 rebounds and 1.9 blocks while shooting 38.3 percent from three with Toronto last year.

For a Raptors team that doesn't face the pressure to win now like Golden State, picking up a potential franchise center in Wiseman is worth taking a small step back this season. The 2020 No. 2 overall pick averaged 11.5 points, 5.8 rebounds and 0.9 blocks in 21.4 minutes as a rookie and could be the answer at center for a Raptors team that has struggled to fill the position after Marc Gasol.

Wiggins is a Toronto native and averaged 18.6 points, 4.9 rebounds, 2.4 assists and 1.0 steals while shooting a career-best 38.0 percent from three last season with the Warriors. Although the Raptors would hate to part with Anunoby, 2021 No. 4 overall pick Scottie Barnes and Wiggins would give them plenty of options at small forward.

Getting Golden State's unprotected first would also be also huge for Toronto, especially if Thompson experiences any setbacks in his return to the court.

Ben Simmons Lands in Los Angeles

Los Angeles Clippers Receive: PG Ben Simmons

Philadelphia 76ers Receive: G/F Terance Mann, PG Eric Bledsoe, SF Luke Kennard, SG Keon Johnson, 2028 first-round pick, second-round picks in 2022, 2023, 2024, 2025 and 2026

After exhausting most of their trade assets to acquire Paul George, the Clippers have now restocked the roster with some young talent and could now be threats to trade for a star yet again.

With Kawhi Leonard expected to miss the majority of the regular season with a partially torn ACL, Simmons would be a nice defensive replacement who would instantly become the best playmaker on the roster.

A backcourt of Simmons and Reggie Jackson alongside George, Marcus Morris Sr. and Serge Ibaka would still be a major threat in the West even without Leonard, especially with Ivica Zubac, Nic Batum, Justise Winslow and rookie Jason Preston (when he recovers from foot surgery) off the bench.

Bledsoe would take over starting point guard duties in Philadelphia and should be re-energized on a title contender after a down year with the New Orleans Pelicans. Mann, 24, made 41.8 percent of his threes last season and dropped 39 points to help eliminate the Utah Jazz. Kennard (44.6 percent from three) ranked eighth in the NBA last season in outside accuracy.

Picking up Johnson, the 21st overall pick in the 2021 draft, and six additional draft picks would give the Sixers some good trade ammunition should they want to make another deal in the future.

Since Philly doesn't have any open roster spots, it would have to include three end-of-the-bench guys (Charles Bassey, Isaiah Joe, Paul Reed, Jaden Springer) or waive a few players for the deal to go through.