The 28-year-old played for Rovers in 2006/07, making 47 appearances, before rejoining former club Crewe.
"I know Chris, I know what he can do and he's a great addition to the squad," Rovers manager Les Parry told BBC Radio Merseyside.
"We have had to survive with just a handful of defenders, so Chris adds much needed strength in depth."
Parry added: "He lives in Heswall and he's moving back up to the area and I'm sure that had a baring on his decision.
"Northampton have done well for us on the financial side. We wouldn't have been able to afford it without their help.
"So thanks to them as well."
The central defender joined Northampton last summer and was a regular for the first four months of the season. He is in Rovers' squad to face MK Dons on Saturday.
Source: BBC Sport
Source: BBC Sport