De Silva, who has been without a club since January when he left Eredivisie outfit Roda JC, is on the verge of joining the Mariners for the 2017-18 Hyundai A-League campaign, according to a report on The World Game.
The 20-year-old is considered one of Australia's more talented youngsters but his career has stalled since leaving Glory in 2015, with a move to Roma having fallen through before he joined Roda on loan.
De Silva managed 16 league matches in 18 months at the Kerkrade-based club.
Speaking to The World Game, Mielekamp declared that De Silva's previous relationship with Mariners coach Paul Okon - they worked together as part of the Young Socceroos - has been critical in negotiations to bring the playmaker to Gosford.
"It's looking positive but until they sign on the dotted line you can never say for sure," Mielekamp said.
"If it all goes through Daniel will be an important recruit for us.
"He and Paulo are close and have been talking for some time.
"We hoped it would happen in January but couldn't get it over the line back then."
The Mariners have already added Alan Baro, Andrew Hoole, Tom Hiariej and Antony Golec to Okon's squad for next season.
De Silva made his Hyundai A-League debut at the age of 15 and has 33 matches to his name in Australia's premier domestic competition.
Roma signed the Perth-born midfielder in June 2014 but allowed him to play the 2014-15 season with Glory, only for the Hyundai A-League club to cancel the transfer just over 12 months later as they had yet to receive payment from the Serie A outfit.
De Silva joined Roda on a two-year loan deal in August 2015 but when he left in January, Perth CEO Peter Filopoulos indicated Glory wouldn't force him to return to Western Australia.