The Scottish Sun says Saints tabled their whopping £12.5 million offer to the Parkhead club last month — which was accepted — only for the player and his agent to snub their deal.
Cardiff then entered the race before pulling out last week.
Lennon revealed: “We gather Southampton have reignited their interest.
“If nothing materialises he will play some of the next game on Tuesday.
“His fitness levels won’t be a major worry for me it’s just getting his football up to speed.”