OXNARD, Calif. — Dallas Cowboys defensive tackle Amobi Okoye is attempting to become the first player to return to the NFL after suffering anti-NMDA receptor encephalitis, a difficult to diagnose and potential deadly brain disease.Okoye, who was in medically induced coma a little more than a year go, was cleared to begin practicing with the Cowboys.He has been on the non football injury list since the start of camp and remains a long way from playing in a game again for first time since 2012.According owner Jerry Jones and his agent Ian Greengross, the Cowboys will take their time and ease him back into full football activities.Greengross said Okoye will "start with 10 percent contact drills and then if no adverse effects it will be increased to 15 percent" and on and on.Greengross said he is "unbelievably amazed and overjoyed" that Okoye is at this point again after being officially diagnosed in March of 2013.He estimated Okoye lost 90 pounds while dealing with the potentially lethal brain disease.Greengross says Okoye weighs roughly 295 now after a long process to rebuild his mind and body back."It's exciting news for us. He's a good football player when he's healthy and playing in this league," coach Jason Garrett said. "He knows our scheme. It's the reason we got him and I think our patience has paid off up to this point, so it will be fun to see him out on the practice field, see what kind of progress he can make."Okoye was a former first round pick of the Houston Texans in 2007. He last played with the Chicago Bears in 2011-2012.Okoye signed with the Cowboys in May in a gamble by the team that he could get clearance to resume his career again and possibly help a defensive line lacking talent.