India's bowling coach Venkatesh Prasad was dumped on the team's return from South Africa, a change widely attributed to an alarming dip in the penetration of Sharma's fast, bouncing seamers.
Dhoni said that void was now being filled by senior teammates, backing Sharma's own unwavering efforts.
'Everybody is guiding him, we've got plenty of experienced cricketers in the side, guys who have played more than 300 one-day internationals, and they are friends,' Dhoni said.
'It is showing in his bowling because he's one of those guys who takes a lot of pressure when it comes to doing stuff in the next session, so you can see him bowling and working hard on his action and his bowling and everything.
'So it's a good sign, you can't always control performance, but you can always control the amount of effort that you put in.'
Theories about Sharma's loss of fire, speed and rhythm have varied, from coaching issues to a common syndrome of underachievement among Indian players who receive much attention and adulation from their cricket-mad country before really proving themselves.
Dhoni said confidence that had ebbed away was on the way back.
'He's just a bit low in confidence, and that happens with guys who are 20-21 and have always seen success, so it's tough for them to deal with failures and that's part and parcel of cricket,' he said.
'You don't always get four wickets, five wickets and as a batsman you don't always score big hundreds or fifties.
'I thought he bowled really well (in Vadodara), he was bowling in the right areas and if you see Ishant, you know when he's bowling well his speed automatically goes up.
'From 127-130km/h, all of a sudden it goes to 135-137, so you know he's bowling with the right rhythm, in the right space of mind.'