Finn Harps manager Ollie Horgan said the latest injury to Damien McNulty is a massive blow as the season enters an important stage.
The Derryman suffered a medial ligament injury after an unfortunate clash with Wexford's Danny Ledwith during the early stages of Friday night's game at Finn Park.
Harps went on to lose 1-0 with Wexford scoring from a set-piece.
Horgan said that McNulty's role in defending set-piece situations has been key for Harps this season.
“We'll miss Damien big time,” he said.
“He goes about his business very well, winning his headers and getting in important challenges.
“Everyone knows what he brings to the team and he'll be sorely missed.”
Just how long the defender remains sidelined, only time will tell. Certainly, the early indications are that Horgan will have to go without him for at least six weeks.
On Friday night, Harps head to Dublin to play Bohemians at Dalymount Park.
It's another critical game for the Donegal side who Horgan insisted this week, are still very much in a battle to avoid relegation.
He might not admit it, but Horgan will have been happy that Wexford failed to build on their win in Ballybofey when they lost at home to St. Patrick's Athletic on Monday night.
“We can't really control what's going on around us,” Horgan said.
“We've got to worry about ourselves.
“We were going well, but we've now lost two games on the bounce. And both goals that beat us came from set-pieces.
“So we've enough things to try and put right ourselves. All I will say is that we are right in the mix. There's still a long way to go and there are a lot of points to be played for.”
When the two sides met in Ballybofey back in early May, the points were shared in a 0-0 draw. Horgan feels Bohs probably should have won that night.
“They missed a penalty near the end,” he said (Ciaran Gallagher saving from substitute Anto Murphy).
“And really, they've probably underachieved this season, given the players that they have in their squad.”
Bohs sit a point adrift of Harps in the Premier Division table.
Also on Friday night, bottom of the table Longford are at Shamrock Rovers, and Wexford are back in action with a home game against Sligo Rovers.
In the other games, Derry City host St. Pat's and Galway United are at home to high-flying Dundalk.