Mane’s disappointing form has coincided with Liverpool failing to fire on all cylinders as usual.
The Reds have lost their Premier League crown to Manchester City, knocked out of the Champions League at the quarterfinal stage by Real Madrid and will finish the season without a trophy.
Liverpool are even struggling to secure Champions League football next season as they currently lie sixth on the Premier League table.
Mane has only scored 14 goals across 45 appearances in all competitions and the Senegal international reckons it has not been the most enjoyable campaign for him.
"This is the worst season of my career. I have to admit it,” the 29-year-old told Canal Plus.
"If you ask me what is wrong I will struggle to give you an answer. Personally I don't know.
"I have always tried to be positive, whether things are going well or badly. I question myself all the time.
"I even underwent a test to take a look at my body. Am I eating the right foods, or has everything changed? But they checked the test results, and everything is fine.
"I need to understand that in life there are ups and downs.
"I will keep on working hard - and perhaps in time this situation will pass."
