Marney is a youngster from Tottenham, who arrives at The County Ground on a month's loan, following in team-mate Johnnie Jackson's footsteps.
Andy King (pictured) has described him as being similar in style to Spurs full back Stephen Carr.
Nightingale, 22, has also signed on loan for a month from Portsmouth, and is set to make his debut against Brentford.
Meanwhile, on the outgoing front, Chris Collins has joined Newport County in a similar deal.
