The Australian international injured his hamstring against Birmingham City on August 21 and had to be subbed off at half-time.
Although it was not a serious problem, it was feared McDonald may miss around four matches but 'Boro first team coach Mark Proctor suggests he may be in line to take on Burnley at Turf Moor on Saturday.
"Hopefully Scott will be back at the weekend," Proctor told the club's official website.
"He started training with the group again on Tuesday so he's hopefully come through that fine and that will help us massively on Saturday."
And Proctor added that if McDonald, or new strike partner Marvin Emnes were to sustain long-term injuries, life would be made very difficult for 'Boro.
"We're concerned about Marvin Emnes, because if something happened to him in terms of an injury it would be unbelievably difficult for us. If anything was to happen to him or Scott we would be struggling a little bit," he added.
The Teessiders currently sit fourth on the Championship table following an undefeated start ahead of the weekend's clash with the 15th-placed Clarets.