The problem troubled the midfielder in the latter stages of the season and forced him out of our final Premiership match against Wolves.
He's unlikely now to play for Wales against Norway in Oslo on Thursday and home against Canada on Sunday.
He said: "We have a couple of games but my shin is playing up again and I have to be aware of it.
"I don't want to come back in pre-season with it bothering me. First and foremost, I'm going to make sure I'm fit and if that means missing a couple of Wales friendlies, that will have to be it.
"I love playing for Wales and don't want to miss any game but that has to be the case this time."
Look out for Simon's final Digger's Diary entry of the season - coming tomorrow...
Simon Davies looks set to miss Wales' friendlies against Norway and Canada later this week as he protects his injured shin.