Otago assistant coach Phil Young said a training squad was continuing to meet twice a week but had been hampered by the poor ground conditions over the past month.
Kaikorai centre Spence had been knocked out in a match about two months ago.
Young said it was a slow recovery for Spence and, although there were signs he would get back to full fitness, it was always best to be cautious concerning head knocks.
Spence has not played for nine weeks.
Young admitted Spence was battling at the moment but he should be fine for the season.
Props Scott Manson and Aki Seiuli have not been sighted all season but Young said they were expected back on the field before the end of the club season.
Manson had an operation on an ankle he injured while playing for Otago last year, and should be back doing contact training in the next week or two.
Seiuli had an operation on his knee and was expected to be playing by now but should be back for his Taieri club before the end of the season.
Young said it was frustrating the time it was taking to get the props back on the park.
But the players were like anyone else in the health system in that they had to wait their turn.
Young said it had been agreed between lock Tom Franklin and the coaching team that the former New Zealand colt have a three-week break in June.
He said that had been agreed in February and the break would give Franklin a chance to see family and also allow him to get his body right.
He said Franklin was looming as a big cog in the Otago forward pack this season and it was vital he was right for the season.
He confirmed Dunedin halfback and former New Zealand colt Brad Weber was no longer in the Otago training squad but that did not mean he was out of the picture for Otago selection.
Confirmation of Fumiaki Tanaka turning out for Otago again was yet to be finalised.
Many clubs have been hit hard by injuries this season, but Young said although there appeared to be more injured players this year, it was about the same as usual.
Players had got bigger and more athletic over the years and that meant collisions were tougher and therefore players took longer to recover from games on Saturdays.
Otago's first game in the ITM Cup is against Bay of Plenty on August 18.
