Donnelly (28) injured his ankle in the opening stages of the Super 14 and, despite playing on for couple of weeks, eventually had to have surgery.
There had been hopes he would get back on the paddock by the end of the Super 14 but that was overly optimistic and his continued absence was felt by the Highlanders, who limped home at the end of the season.
Donnelly plays for the Matakanui Combined club in Central Otago, and so is eligible to turn out for Central Otago.
It plays South Otago for the Topp Cup in Cromwell on June 7.
Otago coach Phil Mooney said Donnelly was training hard and was getting close to returning to the field.
Donnelly had continued to train while recovering from the injury, although his options were limited as he had a moon boot on for part of the time.
Mooney said Donnelly had done some specialist training and his next step was to get back on the paddock and start playing.
The All Black team to play tests against Ireland and Wales will be named on Sunday but, with his lack of match play, Donnelly has no chance of making that.
With there being no New Zealand Juniors tour this year, players only have club rugby on which to fall back to keep themselves in shape, although Maori players can make the New Zealand Maori team.
New Zealand Maori plays a Barbarians team in Whangarei on June 12, followed by games against Ireland and England.
If Donnelly does not make the All Blacks for the Tri-Nations, he will be a useful asset for Otago in its provincial campaign.
Mooney said there were still a couple of places open for the Otago squad, including a second hooker.
Peter Mirrielees is the incumbent but both Jason Macdonald and Sam Anderson-Heather have suffered season-ending leg injuries.
There have been rumours Otago is trying to sign a Super 14-level forward, possibly from the Brumbies, but Mooney said there was nobody on the horizon.
Alhambra-Union hooker Ben Pereira has returned from Australia and will come into contention, while Liam Coltman has been picked as a hooker in the New Zealand Colts team, which leaves for the world junior championships in Argentina at the end of the week.
Mooney said players in the Otago wider training squad were practising at grounds throughout the district.
They had trained at Waikouaiti and Opoho last week and would train at Outram tomorrow.
The idea was to get out and see the province and younger club players would see the team train.
Former Wellington outside back Joe Hill, who has signed for Otago this year, is due to arrive in Dunedin this week, while Otago's other signing, Force midfield back Josh Tatupu, will arrive in a couple of weeks.
It has not yet been decided which clubs they will join.
