Novak Djokovic has admitted that he is currently going through "a challenging process" in a bid to return to the top of the sport.
The former world number one has struggled for form since undergoing elbow surgery, with just two matches being won since reaching the fourth round at the Australian Open.
However, while suggesting that he understands what is required to rediscover his best form, Djokovic has said that his confidence levels are "not at the highest level".
The 30-year-old is quoted by BBC Sport as saying: "I have always believed in myself and that's why I was able to make all my childhood dreams come true, but right now my confidence is not at the highest level.
"The recent results have not been what we are used to but coming back is a process and all I can do now is knuckle down to some hard work. I have had some similar situations in the past but not one quite as challenging as this, so I have to accept it as part of a learning process."
Djokovic is expected to feature at events in Madrid and Rome before taking part at the French Open later this month.
