Northampton defender Brett Johnson has signed a new six-month contract. The 21-year-old played only six games for the Cobblers last season because of hamstring problems.
Town boss Stuart Gray told his club's website: "Brett can certainly play but he has had a lot of injury problems in the last few months.
"We will be doing more investigative work into why he keeps getting the same hamstring injury because it happened four times last season."