The Porcupines have set their sights on beating The Star to claim a ticket for the group stage following a 2-0 home win in the first leg of the first round fixture on Sunday.
“We have to believe that with this performance shown [on Sunday], we can eliminate them," Arthur told Sportsworldghana.
"If any penalty or whatsoever comes, we trust in our goalkeeper Felix Annan to save it.
"Our main motive is to score an early goal there and avoid petty mistakes.
"Moreover, we will inculcate [Etoile's] delay tactics [exhibited on Sunday into our approach].
"I want to tell the supporters that we have qualified already."
The team win aside, there was also personal delight for Arthur who netted Kotoko's second goal. It was his first competitive strike for the side following a move to the club in July.
"I came to Kotoko for business; not to joke, so I am hoping that this scoring feat will continue," said the 25-year-old.
“As a striker, if you work very hard on the pitch without scoring, you have done nothing so I thank God for scoring my first goal.
"Before the game, I knew I would score so I am happy upon fulfilling it."
Kotoko are eyeing a second straight group stage appearance in continental football, having played in the Confederation Cup last season.