Two of Kansas' three biggest stars declared themselves eligible for the draft on Thursday, less than two weeks after helping lead the Jayhawks to their first national title in 20 years.
Rush, who lost his college eligibility by declaring for the NBA draft a second time, is shopping for an agent and likely will start working out for NBA teams in about a month.
Arthur has yet to hire an agent, leaving open the possibility of returning to Kansas if it appears he isn't going to be drafted high enough.
Chalmers, who hit the shot that got Kansas into overtime in the national title game, is still debating whether to declare for the draft or come back for his senior season.
"We knew going into the season ... this particular day was coming," Kansas coach Bill Self said. "Brandon is at a point that it's time for him to move on and Shady [Arthur] owes it to himself to investigate. There's no surprises on what transpired today."
As a high-schooler, Rush said he would have preferred to skip college altogether and head straight for the NBA. His game wasn't ready, so he enrolled at Kansas.
Rush was set to bolt for the NBA last year after his sophomore season, but tore his ACL during a pickup game and pulled himself out of the draft.
After intensive rehab, Rush was back on the court about a month earlier than expected and was slowly eased into Kansas' rotation. It didn't take long for Rush to get his strength back and he averaged a team-best 13.3 points, joining Chalmers, Russell Robinson and Sherron Collins to form one of the nation's best back courts.
There were times when Self had to get on the 6-foot-6 guard about being more assertive, but overall Rush had a strong junior season -- one that may have improved his stock.
The MVP of the Big 12 tournament, Rush is projected as a late first-round, early second-round pick in the June 26 draft.
"It depends on how I plan my workouts," said Rush, whose brother Kareem plays for the Indiana Pacers. "I've really got to get after it these next couple of weeks and get to work and get ready for the workouts."
Arthur was one of the nation's top recruits out of high school, a McDonald's All-American who led Dallas South Oak Cliff to consecutive state titles, earning tournament MVP both times.
An athletic 6-9 forward, he was Kansas' fourth-leading scorer as a freshman at 9.9 points per game and the team's leading shot blocker. But this past season, under the tutelage of former Jayhawks star and assistant coach Danny Manning, Arthur really blossomed.
With better footwork, a new cache of post moves and increased range, he tied Chalmers for second on the team in scoring at 12.8 and was second in rebounding. Arthur was just as active on the defensive end, leading Kansas in blocked shots for the second straight year with 53.
Arthur's athleticism has him projected to go in the first round, and he hopes to improve his positioning through workouts with NBA teams.
"He's going to be a first-round draft pick. The question is where he's going to go," Self said. "We have a feel in the range that he would go in and I think he's totally comfortable with that feel, knowing that you need to go perform well."
Whether Arthur goes at all will be determined by his draft status. If it looks like he's going to be picked in the top 15, he'll hire an agent. If not, he's more than happy to return to Lawrence for a chance at another NCAA title.
Arthur has until June 16 to withdraw his name from the draft.
"I'm in a win-win situation right now," he said. "I'm going into it the right way, without an agent, and I feel very comfortable in coming and trying to compete for another national championship if things don't go the way I want them to."
Chalmers is still trying to figure out if he even wants to test the waters. He's been talking it over with family members and Self expects him to decide in the next 10 days or so.
"He's certainly a guy who could be in the first round," Self said. "He's in the game."