Barnes had been sidelined since he dislocated his shoulder in a twenty20 game before Christmas, and Duffy was sent to the nets to work on his action around about the same time.
The pair reappeared during an intrasquad match at Logan Park yesterday.
Barnes bowled two promising four over stints before lunch which coach Rob Walter described as "Not too bad".
"He’s still a bit rusty for the red-ball stuff but I think he’ll just be excited about the fact he has bowled eight overs," Walter said.
The intrasquad match will conclude today and this weekend Otago A will host Canterbury Country in a development match at the University Oval. It is another opportunity for Barnes to put his shoulder to the test and to press for a spot in the Otago team which will resume its Plunket Shield campaign with a match against Northern Districts in Whangarei next week.
"These next four days will be a good indication of whether he is going to play," Walter said.
If the 24-year-old comes through unscathed and gets selected, he will be making his first-class debut.
Duffy will also be after a spot in that team. His form fell away after he tried to add a yard of pace during the winter and the Otago coaching staff felt it was in the 22-year-old’s best interest to remodel his action.
"It [his action] has been looking pretty good, to be honest. He has looked solid in the nets but this will give us a better indication with him bowling in a competitive environment."
Duffy bowled five overs late in the day and took one for 26.
While Duffy and Barnes are possible starters, Michael Rippon is closer to a certainty.
The left-arm legspinner will return to Dunedin on Tuesday in plenty of time for Otago’s match against Northern Districts.
Opener Hamish Rutherford has a bulging disc in his back and his return date has been put back to March 14. In the intrasquad game, the Brad Wilson XI posted 313 for eight declared with Derek de Boorder scoring 102 and Masoor Khan 99.
Barnes finished with two for 39 and Christi Viljoen also grabbed two for 39. In reply, the Michael Bracewell XI reached 92 for two at stumps. Teja Nidamanuru scored 52.
