Lemina admits the setback has been frustrating.
He told the Daily Echo: “Coming back from that injury I had to start from fresh again, build up my confidence from nothing, while I was watching my team-mates play when I wanted to help them.
“It's just building up that confidence again now."
He added: “The injury was a setback because I was adapting to life in England, but I'm starting to build up confidence in it now.
“I don't think it will be long before I'm back to 100 per cent.
“It took a long time to get over, but now things are getting better and I'm working hard – I'm gaining confidence all the time while I'm training and playing."
Meanwhile, Southampton U23 coach Radhi Jaidi has welcomed Josh Sims' return to fitness.
The striker was back to feature in the 1-1 draw with Reading.
Jaidi was particularly pleased with the return of 20-year-old Sims, whose solid first-half contribution helped Saints control the midfield third, as well praising teenage striker Michael Obafemi.
He said: "Josh Sims played well for 45 minutes, he's been out for a long time. He will only get better with fitness. I also want to name Michael, he really set the tempo for us up top, pressurising from the front. He deserves a clap from the staff."