When Saito tested his arm during a bullpen session Wednesday, he felt better than he had while completing the same drill 24 hours earlier. But the Japanese hurler, who has been sidelined since Sept. 17, still struggled with his command.
"His arm feels pretty good," Cox said. "He was rusty in the bullpen yesterday. The ball wasn't going where he wanted it to on every pitch and he is a strikeout pitcher. He's got great control, and he's got to have that control."
Saito will pitch in an instructional league game Saturday.
Jair Jurrjens, who has been sidelined since Sept. 14 with a sore right knee, will pitch in an instructional league game Monday or Tuesday.
Cox said he remains hopeful that Saito and Jurrjens would be available if the Braves advance to the NL Championship Series.