Salmon injured himself while attempting to catch a ball at training on Monday and after seeking help from a trainer was sent for further examination.
It leaves the 24-year-old in doubt to play in Friday's game against Canberra after he was thrust into the spotlight following last season's win over the Green Machine.
Raiders coach Ricky Stuart labelled Salmon a "weak-gutted dog person" and was suspended for one game and given a $25,000 fine for his extraordinary outburst.
Salmon told media over the weekend he was expecting to wear some flak from the Canberra fans but Yeo, who re-signed a deal with the Panthers until 2027, said they had moved on.
"He has come out and spoken about it in the past … obviously he wasn't happy with it at the time," he told AAP.
"It was a long time and we don't discuss it here and I'm sure they don't discuss it there.
"It probably wasn't an ideal moment."
Stuart's beef with Salmon is the latest flashpoint in the rivalry between the two clubs with Raiders chief executive Don Furner labelling the Panthers "mug lairs" in 2021.
Penrith have won their last four games against the Green Machine.
Despite the fact Stuart's men are 1-3 to start the season, Yeo predicted they would come out firing.
"Every time we play they are always tight games with a bit of heat in it, I'm not sure why," Yeo said.
"You look at the players and their coach - they're hard workers - and it's always a tough contest and they don't want to take a backward step.
"We feel we're the same and we're both clubs who are rich in history."
After so many of their players were involved in the World Cup, Yeo insists it's not panic stations after the reigning premiers began their campaign with a 1-2 record.
"It's not dire straits," Yeo added.
"It's not something we're overly concerned about - our effort is good but we are missing little moments."
