The English duo had been on trial with the La Liga strugglers, but the 50-year-old admits that cash flow issues leave him unable to sign them before the end of the campaign.
According to Sky Sports News, the league has rejected the club's request to register the players due to outstanding financial issues.
"[The two players] have both been brilliant and I would really like to take them and we will be offering them deals for next season," Adams told the news outlet.
"However, we have a cash flow situation at the moment that doesn't allow us to bring them in."
Granada currently sit 19th in the table with 20 points from 32 games, seven points adrift from safety with six games remaining.