The Bees' top scorer is suspended against his former club after being sent off during the bad-tempered 1-0 Boxing Day win at Gillingham.
Experienced striker Carl Cort could earn a recall alongside Ben Strevens, or winger Myles Weston could move forward into attack with Tottenham loanee John Bostock returning to the starting line-up.
On-loan Arsenal goalkeeper Wojciech Szczesny missed out at the Priestfield Stadium with a knock and will be checked over.
Regular keeper Nikki Bull is still recovering from a shoulder operation so Lewis Price, who deputised impressively on Saturday, is on stand-by again.
Defenders Ryan Dickson, James Wilson and Mark Phillips remain injury doubts.
Meanwhile, Bees boss Andy Scott bemoaned the dismissal of MacDonald despite his side's win in Kent on Saturday.
Strevens scored the winner for Brentford in the 42nd minute.
The game became increasingly fractious in the second half with home defender Josh Gowling and MacDonald both seeing red.
MacDonald had picked up his first booking for a dive in the first period and Scott, who was blanked by Gills boss Mark Stimson at the final whistle, said: "There was always going to be another sending-off and that was another chance for the ref to give out a yellow card.
"Charlie's caught the player with a late tackle but the first yellow card should never have been a booking. He didn't even appeal for the penalty. But when you've got a lot of fans jumping out of their seats and shouting at each other because their team isn't playing well, the referee got affected by it.
"It was disappointing what happened at the final whistle. I don't really like Mark Stimson and I'm not going to lower myself to that level."