Burnley winger Aaron Lennon is facing an indeterminate period on the sidelines after undergoing knee surgery earlier this week.
The 31-year-old was restored to the starting line-up for the last-gasp 1-0 defeat to his former club Tottenham last week after cameo appearances off the bench in the preceding fixtures against Liverpool and Brighton.
But Lennon, capped 21 times by England, sustained cartilage damage at Wembley to join the Clarets' lengthy injury list.
Manager Sean Dyche gave no indication of when he expects Lennon to return – meaning he could miss Burnley's hectic festive schedule – but stressed both player and doctor were satisfied by the outcome of Wednesday's surgery.
Dyche said: "He's had an operation, another one unfortunately. We keep getting close to getting everyone back and then a few slip away.
"He's had an operation, simple in the way it is, a cartilage operation, a sort of tidy up situation – there's no timescale on that at the moment.
"But he's happy with it and the specialist was happy with it."
Lennon is likely to be joined on the sidelines by fellow midfielder Steven Defour for their trip to Arsenal in the Saturday lunchtime kick-off because of a calf complaint.
Robbie Brady also suffered a minor injury against Spurs but he and another wideman in Johann Berg Gudmundsson could come into contention as Burnley look to bounce back against the Gunners.
"There's still some way to go before we get everyone fit," Dyche added.
Dyche has been given a boost by Burnley activating the option on extending versatile midfielder Jeff Hendrick's contract by another year.
The Republic of Ireland international joined Burnley from Derby for a then club-record fee of £10.5million two-and-a-half-years ago and has gone on to make nearly 100 appearances in all competitions.
His deal was set to expire at the end of this season but Burnley have secured Hendrick's services for a further 12 months.
Dyche said: "He's done well for us. We have asked a lot of him.
"We have used him in a number of different positions that sometimes aren't natural to him and over time he has delivered good performances for us."
