Both players were forced to go off injured in the second half of the U’s 4-0 defeat at Walsall, on Saturday.
Winger Edwards suffered a hamstring problem, while midfielder Bishop hurt his ankle making a challenge and also had to be withdrawn.
Colchester boss Danny Cowley said: “It looks like Owura had a tightening of his hamstring.
“I think we got it early but we’ll have to see how it settles.
“Owura had a good first half and we thought we were in a good place.
“We were such a threat down the left, in the first half with Owura and Samson.
“But we have to have a bit more about us than just to have one injury disrupt our rhythm.
“Teddy’s was an impact injury.
“He just opened up his ankle in that block tackle, so we’ll have to wait and see on that.”
Colchester are hoping to welcome back Tom Hopper and Harry Anderson for the game at Vale Park.
The attacking duo have both been suffering with groin issues but could return to the squad, after missing the U’s last two games.
Colchester are looking for an instant response tomorrow night, following their heavy defeat at Port Vale.
They face a Valiants side who currently lie fifth in the League Two table, after registering ten points from their last 12 games.
Colchester will come up against a familiar face, with their former skipper Connor Hall set to face the U’s after re-joining Port Vale in the summer.
“It’s another really tough game against a good team,” added Cowley.
“They paid significant money for our captain and have been really aggressive with their recruitment.
“We anticipate another really tough game.
