NEW YORK -- After the Boston Celtics were pushed to the brink of playoff elimination in late April, Kevin Garnett, Paul Pierce and Rajon Rondo held a lengthy huddle in the shower area inside the team's locker room at TD Garden. After the powwow, there was a sense that the trio might have been pondering the future and the potential that Garnett and Pierce were playing their final games in a Celtics uniform.

That became a reality two months later when, on draft night in late June, the Celtics and Brooklyn Nets agreed to a franchise-altering nine-player, three-draft-pick swap.

After formally being introduced as members of the Nets on Thursday at the pristine Barclays Center, Garnett and Pierce sat down for a joint interview with ESPN Boston's Jackie MacMullan (a snippet aired Thursday night, and a longer segment will run starting with Sunday's 10 a.m. "SportsCenter" on ESPN2). Asked about the brother they are leaving behind, Garnett sighed, "Do, Do," invoking his familiar nickname for Rondo (the last syllable of the point guard's last name).

For Rajon Rondo, the Nets trade meant losing one of his best friends on the team in Kevin Garnett. "This whole transition, man, we came in as strangers and bonded as brothers," Garnett said. Elsa/Getty Images

"This whole transition, man, we came in as strangers and bonded as brothers," said Garnett, a person Rondo has previously suggested was his closest friend on the team. "And I say that with Glen [Davis], Kendrick [Perkins], Tony Allen, with Eddie House and [James Posey], just a connection with what it is.

"When Ray [Allen] left [for Miami last summer], it was hard for everybody there. We saw Doc [Rivers] leave [for Los Angeles last month], that blew us out of the water. It's kind of like looking up at the wave coming. And now we're here, so I can only imagine what Do's going through. Obviously, I reached out to him, told him what I was going to do or whatever. I'm sure he's dealing with whatever he's dealing with, obviously he's trying to get back with [rehabbing from ACL surgery in February].

"Whatever that whole universe and his world is presenting to him... It's unfortunate. I had to take away that, what you have established as a brother and as a brotherhood amongst each other, is what you take away from it. Although I'm losing a teammate, I have a friend for life. And that's how I look at it."

Pierce said he talked with Rondo recently and, having been the leader on a team in transition before the Big Three was assembled, Pierce dispensed cautious advice about what lies ahead as Rondo rehabs his knee and the Celtics rehab their roster.

"Right now, he's injured, and I told him this is probably going to be the toughest year of your whole career, mentally and physically," Pierce said. "Physically, you're dealing with an injury. Mentally, you know nothing but winning since you came into the league... You may be put in a situation where you may not win a lot of games. You have to be a leader now; you know me and Kev are not there anymore.

Paul Pierce said he spoke with Rondo recently. "I told him this is probably going to be the toughest year of your whole career, mentally and physically. ... You have to be a leader now." Brian Babineau/NBAE/Getty Images

"You have to go through these times. I've been through them. I explained to him how I went through it. I feel like, I'm one of the best players in the league and now... [Rondo is] going to be in that situation for maybe one year or two years, who knows? But you have to be mentally prepared for it, and that's some of the things we talked about."

Pierce might simply have been speculating, but he had noted earlier Thursday that Rondo is "probably not going to be back until probably December, January, who knows?"

That'd be a change of plans considering that Celtics president of basketball operations Danny Ainge has suggested that the team and the player have eyed a return for the start of the season. That's something Ainge echoed earlier this month while noting that the team and training staff were encouraged with Rondo's rehab thus far.

Ainge did admit that the team might have to take it slow with Rondo during training camp starting in late September, but said being ready for opening night in late October was a reasonable goal.

That's still an aggressive timeline considering Rondo had surgery in February and would be little more than eight months removed from surgery for that partially torn ACL by opening night.

Pierce and Garnett hinted that they have suggested to Rondo to take it slow, maybe noting that there's little rush to get back for a team in transition. But after Rondo had to sit out the final three months of the 2012-13 season, it's going to be hard to keep him pinned down.

Even if it might help Boston's rebuilding process to lose games and deliver a higher draft pick, players and coaches have been adamant this offseason that the team will not tank. Returning veterans have defiantly suggested that they believe the Celtics can still contend with the talent coming back.