A third new team could enter the A-League in 2020 with the demise of Wellington Phoenix seemingly inevitable unless the club drastically improves its off-field performance.

The formal commencement of the expansion process has added further pressure on the Phoenix, whose licence agreement expires at the end of season 2019-20 - the same season when two new teams will join the competition.

Firing line: Wellington Phoenix are facing expulsion from the A-League. Credit:Dean Pemberton

Further extensions will only occur if the club hits certain 'metrics' around attendances and increased broadcast rights, but not even Phoenix co-owner Gareth Morgan is optimistic about reaching them.

If they don't, it paves the way for another expansion outfit to replace the Phoenix in season 2020-21.