And, following the loss of Davies, the arrival of Martin should help to act as a makeweight for a Notts side still needing points to ensure survival.
County currently lie 17th in League One, four points clear of trouble.
After starting his career with non-league Dartford, Martin was signed by Crystal Palace in January 2007 before moving on to Millwall a year later.
Having hit nine goals in 60 starts for Millwall over two years, he signed for Derby, initially on loan, in February 2010, before completing more permanent deal in the summer.
Martin was part of the beaten Millwall team that reached the League One play-off final in 2009.
Source: BBC Sport