The versatile youngster, who had been on loan with the Eagles since August, last week joined the npower Championship strugglers for an undisclosed fee.
Marrow told the club's official website: "We've been talking for a little while so as soon as I signed I was more than happy.
"It's good news for me, I've been happy here. As soon as I heard about the loan move I thought it was a great chance, it's a good level, very competitive.
"It was about getting as many games as I could and I surprised myself a little with how many I did get and I want to push on and get more."