Midfielder Steven Defour's injuries have hindered his adjustment to Burnley and the Premier League.
The Belgium international's fitness has been a source of frustration to club and player.
Defour is doubtful for the trip to Middlesbrough with a knock to his thigh, just above his knee, picked up on Tuesday night against Stoke City.
That came in his first start since January 31st, and the 1-0 win over Leicester City, in which he picked up a hamstring problem.
He also spent three weeks out with a groin injury earlier in the season, and, all told, the one-time club record signing has started only 16 of 30 Premier League games since his arrival from Anderlecht.
Boss Sean Dyche expected a period of bedding in for the former Porto man, but the injury setbacks haven't helped that process: "I think, even with many experienced players who come into the Premier League, it's still difficult.
"I said that when he got here, usually the pace and physicality of the game - the miles on the clock, the tempo and relentlessness.
"He's had a long adjustment to that, and he's had injuries in between. You're on that knife edge of pushing them hard enough to get them up to speed, and trying to ease off enough that their bodies can adapt.
"Their muscle memory grows and they can adapt to what it is.
"It's been a difficult path, just when we got him there, he had an injury, and just when we got him there again, he had a slightly longer injury.
"Then you come away from it and have to rebuild it.
"Then you get more cautious. The other night he got a knock and you say 'we have to get you off quick.'"
With the size of Burnley's squad, and long-term injury to Dean Marney, there is more pressure to get Defour fit than at other Premier League clubs: "Really difficult. Here, we work with a small squad of about 20. The super powers are more like 30, so he could go under the radar while they got him fit and well, used to the football, drop him in and out...it's just different. It's more difficult when you have to do it all at the same time, play him, adapt him, get him fitter, stronger, and used to it all, all in one go, while the team is still winning.
"I'd like to think he'll get there, but there's no guarantee. The ones often you think 'no problem', doesn't happen, the one you think 'absolutely going to struggle', up and running.
"You hedge your bets towards the fact they're going to do well."
Joey Barton has started every league game since becoming available after agreeing a return at the turn of the year, and Dyche isn't shocked by his focus, despite an FA charge for misconduct relating to alleged betting offences still hanging over his head: "Definitely not surprised, he's had an interesting background of various events and he just keeps going.
"Other players, things would play on their mind. He just cracks on.
"It's remarkable single mindedness, but he's that type, he just gets on with the task.
"For us, he's always been 'show me the task, the expectation of what you want, I'll tell you what I can do', and we agree to move forward."