Warburton has signed a three-year WRU deal that will take effect after his current Cardiff Blues contract expires later this year.
Lock Alun-Wyn Jones, though, recently agreed fresh terms with his regional team the Ospreys, turning down a central contract, while Wales full-back Leigh Halfpenny opted to sign for reigning European champions Toulon and fly-half Rhys Priestland - thought to be among a handful of current Wales internationals offered central contracts - has yet to decide on his future.
Warburton used his column for Thursday morning's Daily Telegraph to outline his position.
"I told the union I only wanted to sign a central contract if I could play for the Cardiff Blues," he wrote.
"I am Cardiff through and through and would find it uncomfortable playing for anyone else. If I had not been able to play for the Blues, it would have been back to the drawing board."
The flanker admitted he considered a switch to France following last summer's successful British and Irish Lions tour, but quickly decided in favour of staying in Cardiff and labelled the contract a "great opportunity" to do so.
He added: "I think central contracts can work, and will work. I am sure more Wales players will sign up, and it will become clear that it is not the WRU competing against the regions. It is about everyone working together."
Priestland, who will be involved on Saturday when Wales launch their RBS 6 Nations campaign against Millennium Stadium visitors Italy, said of his own situation: "I would just like to see how things pan out.
"I find it difficult because I don't know all the facts so it's hard to make a fully informed decision.
"The sooner I can sort it out the better. I have spoken to Leigh, Alun and Sam, and they all feel a weight off their shoulders (after deciding their futures).
"I think it would be better if I stayed in Wales, but nothing is set in stone yet."
Regional Rugby Wales (RRW) issued a statement expressing its surprise at "the introduction of one individual national contract at this particular time".
It said the Warburton development had left the RRW "bemused", adding that the organisation "would question the strategy behind the bizarre action by the WRU, given that a final agreement on the future of Welsh Rugby has yet to be reached".
The statement continued: "The regions would ask what kind of message this sends out about Welsh rugby to our colleagues in the game across the world.
"The regions would also question how one national contract works as a constructive and sustainable strategy for the whole of Welsh rugby, given that we have some 200 professional players in Wales contracted to the regions."
As things stand, Warburton would be unable to play for the Blues as the regions will not select centrally contracted players without an agreement being reached.