Kyrie Irving admitted it has been tough to watch the Brooklyn Nets from the sidelines as he marked his return to the practice court on Wednesday.

Irving returned to Nets' practice for the first time since preseason after the franchise decided in October to make him unavailable due to New York City's vaccine mandate and his unvaccinated status.

The Nets reversed that decision a fortnight ago when they announced the 29-year-old would return on a part-time basis for away games, despite remaining unvaccinated, with the side short on numbers following a surge of players in the NBA's health and safety protocols.

Irving's return to the practice court was delayed by him entering protocols a day after the Nets' announcement earlier this month, but he has now been cleared.

"I'm incredibly grateful just to be back in the building," Irving told reporters speaking for the first time publicly since mid-October. "Welcomed back with open arms [from] my teammates, the whole organisation.

"I'm not going to lie, it has been relatively tough to watch from the sidelines with everything going on in the world. I know everybody is feeling it. Just praying for everybody to be healthy during these times."

Irving will only be permitted to play away games and head coach Steve Nash said he would need a couple of weeks to get into NBA-ready condition.

"If I get the opportunity to get on the court and play with my teammates, even if it is just on the road for away games, I am grateful for the opportunity," Irving said.

"I've missed so much time. It's my first day back around the block with the guys and it felt like it's been a long time.

"It's only been, what, three months or so, but it has felt like the days have been slowly crossed off the calendar while I am sitting at home. When I thought about [returning to practice] last night, I could barely sleep.

"I understood their [the Nets'] decision and respected it. I really had to sit back and think and try not to become too emotionally attached to what they were deciding to do. I had to really evaluate things and see it from their perspective, meaning the organisation, my teammates.

"I really empathised, and I understood their choice to say if you are not going to be fully vaccinated, then you can't be a full [participant]."

The Nets are currently top of the Eastern Conference with a 23-9 record and play the Philadelphia 76ers at the Barclays Center on Thursday, which Irving will be unavailable for.

Five of the Nets' next six games are at home.