Graham Potter has conceded Swansea City may pay a heavy price for their impressive 3-2 victory at Brentford through an injury to Martin Olsson.

The Sweden World Cup full-back was carried off on stretcher with an Achilles tendon problem early on during the first-half of his team’s victory at Griffin Park.

Olsson is due to have a scan to assess the severity of the injury, but the likelihood appears to be he will be sidelined for some time with Potter admitting: “It does not look good, to be honest.

“It is in his Achilles area but we will have to get it scanned before we know the full extent of that.”

There was an eight-minute delay with just four minutes gone as Olsson – one of the few survivors from Swansea’s Premier League days to remain a regular starter – was given lengthy treatment.

Potter has former Cardiff City full-back Declan John to call upon, but a long-term absence for Olsson could mean a re-think on January transfer window priorities.

Potter was pleased with the way his team responded to three successive defeats as they went 3-0 ahead against the Bees, although they had to survive a spirited home comeback.

The Swans were hanging on at the end and Potter added: “We were three up and doing things really well and then we conceded and the home crowd turned.

“We knew the game was still alive and started the second half well, had chances to put the game to bed, but didn’t take them and then anything can happen.

“Any three points will be hard fought in this division. We had a little luck and they missed some good chances so all in all it was a great game for the neutral, but horrible for me and their manager.”

Wayne Routledge, a Chris Mepham own goal and Leroy Fer put the visitors three up in a dream first half that left the rattled Bees reeling.

Ollie Watkins and Said Benrahma gave the hosts hope but squandered a string of clear-cut chances to pull off an unlikely comeback.

Brentford manager Thomas Frank said: “We felt the draw at West Brom was a turning point that would give us momentum that we could build on back at Griffin Park.

“We prepared well, trained well and then we are behind after 20 seconds,.

“The first half-an-hour was like a horror movie and it got more and more scary. We are making too many simple mistakes.

“They had three chances on target and scored three goals within 27 minutes and you think, ‘How does that happen?'”