The Mali international teamed up with the Saints in the summer from Belgian First Division A club Standard Liege and impressed in his second game for the side.
Djenepo opened his goal account two minutes after his introduction as a second-half substitute with an audacious goal against Brighton before Nathan Redmond sealed the victory for the St Mary's Stadium outfit.
“He wasn’t on the pitch very long before he made the first goal – it’s fantastic for him,” Hasenhuttl told the club website.
“The fans will love him immediately, but don’t put too much pressure on him. He must learn a lot, especially against the ball, but I like this guy – he’s very positive."
Djenepo performed his initiation song before their clash with Brighton and Hasenhuttl admitted he preferred him to score than listen to him sing.
“After dinner he had to sing for the team and he did it in an interesting way. His scoring is better than his singing.”
Djenepo will hope to start when Southampton take on Fulham in Tuesday's League Cup tie.