Mariners owner Mike Charlesworth insists the 20-year-old star doesn't want to go, the club don't want him to go and if he's forced to join Ante Milicic's squad in January it will be of "no benefit" to him and will "devalue the A-League".
The biennial competition, to be held in China next month, is not a qualification pathway to the 2020 Olympics, but Milicic has chosen to select the best available players.
Socceroos Alex Gersbach, Ajdin Hrustic and Riley McGree were named in a 23-man squad along with 15 A-League players including Adelaide United's first-choice goalkeeper Paul Izzo and striker George Blackweod, Western Sydney's Keanu Baccus, Melbourne City's Bruce Kamau and Stefan Mauk and Melbourne Victory's Thomas Deng.
They could all miss up to five domestic games, leaving their clubs fuming.
In what is effectively a test case on whether FFA can continue to compel clubs to release players outside designated FIFA dates, the Mariners will know the outcome of their gambit when the case is heard by an Independent FFA tribunal in the coming days.
They have the backing of the other nine clubs, with the tournament seen by the club owners as having "very little significance".
If the Mariners are successful in keeping De Silva in Gosford, the implications could be grave for the integrity of Milicic's squad.
Charlesworth has no objection to call ups for fringe keeper Thomas Glover and Trent Buhagiar, but has drawn the line under influential first-teamer De Silva.
"It's fine for squad players to go (there is a limit of three players per club), I think that helps develop them," he said.
"But we don't believe that players like Daniel, who is on the verge of the Socceroos squad, should be forced to play in a tournament which will do nothing for his career.
"He's better off staying in the A-League ... what value is there in Daniel going to China.
"Losing players of his quality diminishes the quality of the competition in what are very difficult and challenging times.
"Daniel doesn't want to go, and nor does the club or the coaching staff want him to.
"This severely damages the CCM product we are desperately trying to market and subsequently the quality of the league.
"Most importantly, it's ultimately detrimental to the careers of players like Daniel."
Charlesworth contends that De Silva continuing to develop in the A-League is far more beneficial for his international future, pointing out that the spine of the Socceroos emerged from the Mariners, from Mat Ryan and Trent Sainsbury through to Mile Jedinak and Tom Rogic.
"That's because we know what we're doing in developing players through playing A-League matches," he added.
Taking a broader swipe at FFA and its besieged chairman Steven Lowy, Charlesworth made clear his displeasure at Head Office sanctioning the selection of squad which will see clubs lose key players at a vital juncture.
"Steven Lowy was appointed chairman over two years ago stating that the priority was the A-League," he added.
"This is just another example of him not complying with what he's previously said.
"As far as he's concerned the Under-23s get preferential treatment over the A-League.
"People come to watch our best players and we can't play them.
"We are weakened and so is the league at a time when we can least afford it.
"I am sure other clubs will follow suit if we are successful (in contesting it).
"It's not that we want to stop players going ... it's a question of which players go.
"This situation won't enhance the reputation of the A-League and does nobody any good."
On Tuesday night, FFA was sticking to its guns, wanting to give younger players the chance to experience an elite tournament environment to stand them in good stead for any future national team duty.
"FFA will defend its right and responsibility to select and prepare national teams for international competition and to provide those opportunities to Australian players," a FFA spokesperson said, noting it had the right to do so.
"The ability to do this outside of FIFA international windows for AFC tournaments is included in existing formal agreements with A-League clubs."
A-LEAGUE OLYROOS MISSING IN JANUARY
How reliant are the A-League clubs on the 15 Olyroos called up for the under-23 Asian Championships next month? A tally of their minutes and appearances in the league to date.
Adelaide United - 2424 minutes - George Blackwood (11 appearances), Paul Izzo (11), Ben Garuccio (9).
Melbourne City - 1557 minutes - Stefan Mauk (11), Bruce Kamau (9), Ruon Tongyik (0).
Central Coast Mariners - 1404 minutes - Daniel De Silva (11), Trent Buhagiar (8), Thomas Glover (4).
Melbourne Victory - 900 minutes - Thomas Deng (10).
Western Sydney Wanderers - 798 minutes - Jonathan Aspropotamitis (5), Jaushua Sotirio (5), Keanu Baccus (2).
Perth Glory - 661 minutes - Brandon Wilson (10).
Newcastle Jets - 103 minutes - Nicholas Cowburn (5).
