"The over-riding factor is to come and play some games and help the team out any way I can," McLeod told Northampton's official website.
"I've known Platt for a number of years now and still keep in contact with him. It is nice to come and have a few familiar faces here.
"I was at the Dons with Matty Doumbe as well so I know him, so it is always good to have a familiar face when you come to a new club."
McLeod could make his Northampton debut against Accrington Stanley on Saturday.