Jayson Tatum admitted there were tough times as pundits questioned whether he and star teammate Jaylen Brown could ever win at the highest level, but insisted it only pulled them closer together.

It was a stark fall from grace for the duo after an incredible start to their career when - with Brown drafted in 2016 and Tatum in 2017 - the pair made it to the Eastern Conference Finals in Tatum's rookie season.

They made it back to the Eastern Conference Finals in 2020 during the 'bubble' season, but struggled to follow it up on the way to being dominated by the Brooklyn Nets in the first round of the 2021 playoffs.

It was a poor start to this season as well, as injuries and adjusting to new coach Ime Udoka had the Celtics in 11th place as late in the season as January 16, but during NBA Finals Media Day Tatum said he never doubted what he could accomplish with his partner-in-crime.

"I honestly believe it's just two young, extremely competitive guys who just really want to win at all costs," he said.

"Obviously, that made us closer in a sense of, we just wanted to figure it out. Not necessarily prove people wrong, but just prove that we can win, and put ourselves in the position to do that.

"And it was tough – at a certain time we were three games under .500, and the 11th seed. I'm sure not many people would have thought we'd have got to this point.

"But there was always a sense of belief between us and the group that we were capable of figuring it out."

He added: "It was very frustrating, head-scratching and all those types of things. It was more so just how can we figure it out, not 'we can't do this' or 'we got to figure something else out'.

"It was tough, there were definitely some tough moments – because I always remember the fun moments.

"My first year, going to the Conference Finals, and the 'bubble' year, going to the Conference Finals – when we were winning all the time.

"At the beginning of this year, every game was like 'I don't know if we're going to win' – it was a lot tougher than it probably should be, and that was something I wasn't used to."

Tatum also addressed feelings of personal doubt as he quickly rose to super-stardom at a young age.

"I'll be honest, there's been times when I've questioned 'am I the right person to lead a group like this?'," he said.

"I never, like, doubted myself, but you know, just moments after some of those losses in the tougher parts of the season, it's human nature to question yourself and things like that.

"But always stick to what you believe in, and trust in the work you put in. It can't rain forever."

Brown shared a similar sentiment about his All-NBA First Team running-mate, saying he always felt like they would figure it out.

"I think that we've been able to win in our career," he said. "Last year, obviously things didn't work out for other reasons, but this year I didn't feel like it was because of the way we played basketball.

"I just think things didn't come together at the right time. Early on in the season I was injured, I missed about 15 games, and the narrative isn't going to say that, they're just going to say 'you guys lost' – it doesn't matter what the excuse is.

"We had a first-year head coach and we were trying to figure it out, and we play in a city that has no patience for any excuses, so we didn't make any, but as things started to come together, we got healthier.

"We made a couple of moves in the front office that were vital for us, and things started to fall in line."

He added: "I've always had unwavering faith, even in the midst of situations that look like things are about to go in a direction that nobody wants to go in, I've always had faith in this group, and this organisation, and myself that we'll be alright.

"In those moments where we lost, I knew we had so much to learn, I knew that I had so much to learn, so if anything it was more encouraging to learn from my mistakes, and get better for the next year. 

"I didn't have any time to question myself, or question what's in front of me, because my belief was so strong."

After making it to the biggest stage, Tatum reflected on what it feels like to be making his dreams come true.

"I just kind of reverted back to being a kid – watching the Finals every year growing up," he said.

"Every kid can imagine themselves being in the NBA, and being in the Finals, but actually living out your dream in real-time is a surreal feeling. Sometimes you have to pinch yourself.

"I walk in and I see this [NBA Finals-themed] backdrop – and it's like 'damn, I am in the Finals' – so I'm just trying to take all this in, and just enjoy the moment.

"It definitely does feel different. There's a lot more media, a lot more obligations.

"So it definitely does feel different – I'm sure basketball is still basketball – but all the things leading up to it are unlike anything else."