The deal, which the Irishman signed in August on his 17th birthday, has been awaiting international clearance from FIFA and had prevented him from playing competitively for the first team and the U18 team.
The O’s number 25 has now signed a deal which runs until June 2020 and can now be considered for first-team action.
Director of Football Martin Ling told leytonorient.com, “We’re really pleased for Shadrach. It has become a bit of a saga. He couldn’t play any football, only friendlies for us. He’s now got that international clearance, he’s now able to be involved in the first team and I know he’s in the 20-man squad for tomorrow’s game”