An inner ear infection has ruled Swans defender Nick Smith out of Saturday afternoon’s clash with Port Adelaide at AAMI Stadium.

Smith’s condition, which has failed to improve throughout the week, has resulted in the 23-year-old suffering a slight case of vertigo.

Swans coach John Longmire said Smith had been unable to train all week because of the infection.

“He’s got a virus that has knocked him around pretty badly,” he said.

“It’s a severe inner infection, so it’s meant he’s got a touch of vertigo, so he’s not playing this week.

“He’s an important player for us but hopefully he gets better soon.”

Coincidentally, Smith was also a late withdrawal for the Swans only Adelaide game last season, when he was ruled out with a hamstring injury.

Longmire said the coaching staff will make the decision about who will take on Smith’s role in the team after the final training session this morning.

He said new recruit Tony Armstrong, who was sidelined throughout the pre-season with injury, could be one who comes into consideration for the trip to Adelaide.

“It’s always the case of weighing up whether we need to bring in another player that plays that specific role,” he said.

“(We’re assessing) whether (Tony) Armstrong is a week or two away or whether he needs a couple more games (in the reserves).

“We’ve also got players (from last week’s squad) there who are pretty flexible and can play a number of different roles, so that’s what we’ll consider after our training session.”

Smith will be joined on the sidelines by Lewis Roberts-Thomson who could miss up to three weeks after suffering a fractured cheekbone in the round two win over Fremantle.

Re-visit sydneyswans.com.au at 6.25pm tonight when the full team to face Port Adelaide is released.