He had his ankle x-rayed but Plymouth boss Paul Mariner confirmed: "Fortunately, nothing was broken but he has gone back to Burnley to be assessed by the medical staff. I have been told by our people he could be out for between three to five weeks which isn't ideal to say the least.
"But he wants to stay with us and we want him to stay so, hopefully, he can come back at some point. He's only a young lad and they are quick healers.
"If he's out for four weeks, say, at least he could still help us a little bit towards the end of the season."
Eckersley had an impressive debut for the Pilgrims when he won the man of the match, and he'd settled into the team well until this injury.