The 34-year-old McDonald was injured Oct. 13 in Dallas and has dealt with multiple concussions in his career. He has been skating on a regular basis since Dec. 23.
The Blues wouldn't say when McDonald would return, but Sunday is the likely target after McDonald had another good day of practice Friday. The Blues will face the Colorado Avalanche on Saturday night and don't want to play McDonald on consecutive days.
"I felt really good today and probably I feel like I'm ready to play," McDonald said after practice. "I feel really good. I've been clear on the ice for a while now. I'm real close. Today it felt really good. I got to do some more line situations and it felt good. I'm looking forward to getting back in ... whenever that is."
McDonald indicated that he didn't know when he would return, but he has been symptom-free. The decision is based on when he's ready and when team doctors and neurologists are comfortable in releasing him.
"Obviously, that's a decision to be made with the training staff, the doctors and, obviously, the coaching staff will have a say with that," McDonald said. "I feel I'm real close. That's all I'm going to say.
"It's certainly not one person's call. Obviously, they're listening to me and they want to make a decision that's going to be safe for me and my health. I'm in the same position. I don't want to put myself in a dangerous position. Everyone's going to kind of have a say, find out what's best for me and also what's best for the team. We'll see what it is."
Blues coach Ken Hitchcock continues to wait.
"It's really up to Andy now," Hitchcock said. "When he's comfortable, I'm sure he's going to come knocking on our door and say, 'I'm ready to go.' But we haven't had that knock yet, so he's a fifth-line player."
McDonald has two assists in three games this season. He has 165 goals and 448 points in 626 NHL games in 11 seasons.
"Adding Andy McDonald to your lineup's going to definitely boost your team," teammate Chris Stewart said. "He's a great player offensively. He's one of our big-time leaders. We've definitely been missing him and we can't wait for him to come back."
Also Friday, the Blues placed center Jason Arnott (shoulder) on injured reserve. Alex Steen (concussion) hasn't played since Dec. 27 and Matt D'Agostini (concussion symptoms) will miss the games this weekend.