Oakley, along with Liam Sercombe, Alan Gow and Tommy Doherty, is currently sidelined, with none of that quartet close to a return.
The Grecians have had to make do with virtually a whole midfield missing, although the loan acquisitions of Lawson D'Ath from Reading and Brighton's Anton Rodgers have boosted the ranks.
The former Leicester man's absence has been a huge blow for Paul Tisdale's side but he believes his side are well equipped to prevail in the face of adversity.
"It's our whole midfield and a hell of a thing for the club to overcome really," he told the Western Morning News. "It's four strong players in the team and all with long injuries.
"You can get by if you miss them for a few weeks but Alan has been out for a while now, Tommy is still a few weeks away and Liam is out for the whole season with me.
"It is unfortunate, but the team reacted well against Bradford. Hopefully we can just keep the momentum going."