"He has indicated to me that this is it," Kupchak said Thursday in a radio appearance with SiriusXM NBA Radio.
Bryant is scheduled to make a league-high $25 million in his final contract season -- his 20th -- with the Lakers. But there's speculation that Bryant could play beyond next season, and Bryant said he hasn't ruled out that possibility.
"I think first and foremost, he's on the last year of a deal," Kupchak told SiriusXM NBA Radio. "There have been no discussions about anything going forward. I don't think there will be."
Bryant will be 37 years old when next season begins, and his past three seasons have ended early because of injury. He played only 35 games last season before suffering a season-ending shoulder injury.
"A year from now, if there's something different to discuss, then it will be discussed then," Kupchak said of Bryant potentially playing beyond next season. "I talk to him from time to time ... and he is recovering. He's running. He's getting movement and strength in the shoulder. We expect a full recovery, but yeah, he's much closer to the end than to the beginning."
Bryant took to Twitter on Friday afternoon to say nothing has changed in regards to his plans for the future.
My thoughts on next season being my last season are the same as the last time the media asked me last season #nadanew
— Kobe Bryant (@kobebryant) May 22, 2015
Because of the uncertainty about Bryant's future, Kupchak said he's unsure if there will be a farewell tour next season.
"It's kind of up to the player, if they want to do something like that," Kupchak said. "And it also may take away some options a year from now and put a player in an awkward position, but he will be recognized appropriately with great gratitude when it is time."
Kupchak was also asked if it's important for free agents to have clarity on Bryant's future plans with the Lakers, particularly if they're wary of joining the team while Bryant is still playing, a notion that has been reported in recent years.
"I think it is clear," Kupchak said. "He's on the last year of his deal. There have been no discussions [about playing beyond next season]. He hasn't indicated that he wants to continue to play.
"But if there is a player out there like that, that won't come here for that reason, then we don't want them. Every great player is demanding and focused, and if you don't want to play for a guy like him that's driven to do nothing but win championships and work hard, then you shouldn't be here. You should go someplace else."
Kupchak also said that about a decade ago, Bryant wanted to be involved in just about every decision the organization made, including which players it drafted.
But with the Lakers holding the No. 2 overall selection in the June 25 draft, Kupchak said he doesn't expect Bryant to have much -- if any -- input on who the team selects this year.
"Seven or eight years ago, he just backed away and said, 'You guys know what you're doing,' which was flattering," Kupchak said in a radio appearance Thursday with ESPN's Colin Cowherd.
"[He said,] 'I'm just going to do what I do during the offseason. If you need me, I'll help recruit. If you want my opinion on a player, give me a call. I'll be at the gym today, let's sit down and get lunch, let's talk.' That's kind of where we are today.
"... He knows about the guys at Duke, Kentucky and North Carolina, but I don't think he wants to be involved in the draft at all."
Kupchak reiterated that Bryant is still involved in recruiting free agents.
"He's more than willing [to call a player] every time I ask him," Kupchak told SiriusXM NBA Radio.
But Kupchak can't yet publicly say whether that includes Rajon Rondo, the mercurial four-time All-Star point guard.
"I know I can't comment on free agents," Kupchak told Cowherd. "But I mentioned earlier, we have two things: No. 1, we have a rookie [Jordan Clarkson] who had a good year who's a ballhandling guard who can also, I think, be in the backcourt with another ballhandling player. I think that would work.
"But the other thing we have is, we do have a lot of cap room. We feel like we do have to be aggressive. Getting the [No. 2 overall] pick takes a little bit of the pressure off to do something borderline this summer [in free agency]."