The first domino is on its way to the ground. If that’s where the tumbling stops, the Kansas University basketball team still shapes up as Final Four-caliber next season. That’s a pretty big “if,” since it was Julian Wright, not Brandon Rush, who was the first to decide he is leaving for the NBA.

As talented and enthusiastic as he is, Wright was not the most indispensable player on the Jayhawks. Rush, largely because of his shut-down defensive abilities against anybody from a shooting guard to a finesse power forward, would be the most difficult player to replace. Even if Wright had come back, there would be no easy answer to the question of where KU would turn to replace Rush. Answering how to replace Wright is easier. Darrell Arthur is not the passer Wright is and not yet the rebounder, but he is a better shooter and similarly gifted athlete.

Wright, who averaged 7.5 points and 4.5 rebounds in the two West regional games in San Jose, Calif., repeatedly said after the loss to UCLA that he was “100 percent” certain he would return for his junior season. He changed his mind, as is his right. Assuming he doesn’t change it back, and assuming no shockers (Arthur, Mario Chalmers) follow him out the door, Rush’s decision becomes the X factor that defines Kansas as either a top-five team or a top-20 one.

Of course, that reality can’t factor in Rush’s decision because his financial future could depend on him making the right call.

First, consider what KU’s lineup would look like with Rush back for his junior season. He would join two of the three star guards (Chalmers, Russell Robinson, Sherron Collins), plus Darrell Arthur and either Darnell Jackson or Sasha Kaun in the starting lineup. Cole Aldrich, ready or not, lends help up front. Brady Morningstar, Rod Stewart, Jeremy Case, Tyrel Reed and walk-on Conner Teahan compete for the final spot in the rotation.

That’s the best-case scenario, and not a bad one. It’s not the most likely one. It appears Rush is in a spot where he will need to hear a compelling reason to return to school, rather than needing to be talked into seeking an NBA career.

Rush shut down USC’s Nick Young, slowed Texas freshman Kevin Durant and took Florida’s Joakim Noah out of the game for a long stretch. All three of them are lottery possibilities. Nobody left on the Kansas roster matches Rush’s defensive presence. Morningstar is the closest among replacement candidates to being an offensive play-alike. Even so, not too many teams could boast a starting five as fast as Collins, Robinson, Chalmers, Arthur and Jackson. It would have an undersized underdog quality to it. It wouldn’t win 33 games, but it wouldn’t be boring.

High turnover is the cost of doing business at the elite level and a big factor in the increase of parity in college basketball. Losing players early to the NBA makes a school all the more appealing to high school stars, and the cycle repeats. Land a class of big-time recruits. Break them of bad habits the first year. Sweat out the next season, knowing it’s the best shot at the Final Four with that group. Retool for a year. Land another huge class. Rinse and repeat.

Expect a monster recruiting haul for Kansas next November, then relax and watch a smallish, quick team contend for a Big 12 title.