The 21-year-old has impressed in the topflight since playing a key role in Arrows' MultiChoice Diski Challenge triumph in 2015/16, most recently setting up Musa Bilankulu's decisive header in the 1-0 win over Platinum Stars in the Nedbank Cup on Saturday.
"He's been working very hard on set-play deliveries. He and [Kudakwashe] Mahachi are our designated set-play specialists," said Larsen.
"We are happy that all the hours we put in at training is coming to fruition and as a coach that is most pleasing. His [Sibiya] confidence is high at the moment but still there's a bit of inconsistency in his play.
"There are areas we know he can do better, especially towards the second half of matches he seems to go off the boil a bit. But he's getting stronger and he's still a growing young man. He's still going to get physically stronger and with a lot more experience behind him I'm sure he'll develop into one fantastic player."
Meanwhile, Larsen is grateful Arrows chairperson Mato Madlala organised a chartered flight for tonight's clash against Polokwane City at Old Peter Mokaba Stadium in light of Friday's visit of champions Mamelodi Sundowns.
"Great support from our chairlady, she's saving our legs for Friday's game against Mamelodi Sundowns," said Larsen ahead of the 19h30 kick-off against Rise and Shine.
"She's chartered a flight for us to go in and out of Polokwane on the same day and we really appreciate that support from the management.
"Having said, we'll go there and battle. It is six points to fight for in the coming week, and two wins and two draws or three wins at least can really consolidate a good position for us to finish the league [in the top eight]."
Seventh-placed Abafana Bes'thende and City both have 31 points from 24 matches, having played to a thrilling 3-3 draw in the reverse fixture in November.