Rakuten Eagles first baseman Japhet Amador has filed an appeal with Nippon Professional Baseball over his six-month doping suspension, a team executive said Wednesday.

Rakuten's director Hiroshi Abei clarified that the appeal was filed to allow for an investigation into the circumstances in which Amador ingested the drugs chlorthalidone and furosemide. The deadline for filing an appeal was Tuesday.

(Supplied photo)

Following an exam on June 13, Amador tested positive for the two banned substances, which can serve as masking agents for performance-enhancing drugs.

The 31-year-old Mexican slugger, who had been batting .269 with 20 home runs over 62 games this season, has denied intentionally taking any banned substances.

Rakuten slugger Japhet Amador gets 6-month doping ban

Abei explained that he filed the appeal on Amador's behalf out of respect for the player's wishes.

"Rather than expressing dissatisfaction with the ruling, I want to find out precisely how this occurred," Abei said.

Amador will have until Sept. 4 to offer an explanation, after which a special anti-doping panel will be convened and a decision will be passed down within 30 days.