It's back to the drawing board for Gilas Pilipinas in its quest to recruit a naturalized player who can enhance the team's winning chances in the FIBA World Cup next year.

Attempts to naturalize two candidates went down the drain when prime targets Noah Vonleh and DJ Wilson were signed by separate squads from the National Basketball Association (NBA).

Vonleh just inked a one-year contract with the Boston Celtics while Wilson and the Toronto Raptors agreed on a multi-year contract extension.

Now that Gilas' prospects are no longer available, head coach Chot Reyes said he has put in motion the search for new candidates.

"We have to look again because those are two prospects that we lost. We have to find new (candidates) again," Reyes said.

"Well, they were our targets but they were signed by the NBA."

With the aim of forming the strongest possible lineup for the FIBA World Cup, the Samahang Basketbol ng Pilipinas wants to form a four-man pool of naturalized players to beef up the options.

Ange Koume is the lone naturalized player so far, but the federation is high on tapping Jordan Clarkson for eligibility as well.

Vonleh and Wilson, meanwhile, would have been solid frontcourt options for the team.

The 6-foot-10 Vonleh was a ninth overall pick during the 2014 rookie draft and saw action in seven NBA teams before playing for the Shanghai Sharks in China.

The 26-year-old Wilson was also a formidable choice as he averaged 7.5 points, 4.0 rebounds and 1.3 steals in his previous season with the Raptors.

Still, Reyes and SBP are eager to lock in a new prospect with only one year left before the prestigious cagefest.

"We are looking for naturalized players that can play for the World Cup, but if they're in the NBA, it will be hard for them," Reyes said.