D'Arcy started at No.12 in Ireland's win over Wales on matchday one but a foot injury sustained in the loss at home to England cut his Six Nations short, with Marshall - 11 year's younger than D'Arcy - getting the nod to start against Scotland.
The 22-year-old started off against Scotland with the kind of line-breaks that were once Darcy's forte and featured in Ireland's remaining three games before concussion cut his Championship short against Italy.
The duo will lock horns this weekend in the Celtic League and speaking ahead of the match, D'Arcy was quick to give his heir apparent a glowing review.
"He's a really solid player, does everything - he has got the full array of talent, he's a good kicker, a good distributor and a solid guy," said D'Arcy.
"So he's done very well when he's got his opportunity and you have to take your hat off to him. Hopefully he's back this week because I enjoyed playing against him, the last time we played. We'll see how we compare against each other again."