Tony Pulis is sweating on the fitness of striker Rudy Gestede after his early withdrawal in Middlesbrough's most recent pre-season friendly.
The striker lasted just 24 minutes of the 4-3 defeat to Accrington Stanley after an awkward landing within the first ten minutes of the clash.
Gestede was initially able to continue, but after suffering further discomfort he later made way for strike partner Britt Assombalonga.
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And following the game, Pulis confirmed that the former Aston Villa man had injured both of his ankles.
Such news will no doubt start alarm bells ringing, with Gestede having missed portions of last season with ankle problems.
Speaking to the Teesside Gazette, Pulis said: “Rudy has landed twice when he has gone down and he has hurt his right ankle and then his left one.”
There is no timescale on the 29-year-olds return as of yet - although doubts will be cast over whether he will be fit for Boro's season opener at Millwall.
Meanwhile, fellow forward Martin Braithwaite has returned to the Middlesbrough squad following an extended holiday.
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The Danish striker played in all four of his nation's World Cup games and was then given an extended leave period in order to properly recover.
But the club have no confirmed that Braithwaite is back on Teesside, although he faces an uncertain future having fallen out of favour last year.