Gillingham: Martin Allen backs Akinfenwa-McDonald partnership
The duo, who contributed 36 goals for the Gills in 2010-11, have not been fielded at the same time this term.
Allen told BBC Radio Kent: "Will they play together at some point? Yeah.
"What happened three years ago isn't any of my business. I have got the players I have got now. Everyone will get a chance to play."
Gillingham, who won the League Two title last season, have made a slow start to life in the third tier, picking up just one point from their first three league matches and scoring just one goal.
Allen says all of his forward players will be handed opportunities to impress.
He continued: "I have also got Antonio German as well. He has been fantastic in training and played very well in a game the other day.
"At the moment, Danny Kedwell has been on fine form. He has areas of games that help us.
"He is our main header of the ball when defending corners. He heads it out of our box more often than any other player and not many people realise that. He is doing a fantastic job for our team."
Meanwhile, Allen says he now wants midfielder Charlie Lee to remain at the club.
"Charlie has been superb in both the games he has played," said the former Cheltenham and Brentford boss. "He has been our best player, without a shadow of doubt, in both games and it is great to see. I don't want to see him go.
"Without going into too much detail there are other issues to take on board. I won't talk about that publicly. At the moment Charlie is our player and is playing in the team. That is the bottom line and all that really matters."