Striker Griffiths has pulled out of Alex McLeish’s squad for the Nations League clash in Haifa after announcing he needs to “work on his fitness”.
The move has been viewed in some quarters as an angry response to being dropped for last month’s clash with Albania.
But McGregor fully expects to see his Hoops colleague back with the national team soon.
He said: “We are disappointed not to have him here, we know how good a talent he is. We know what he can give the squad.
“But ultimately he knows his own body and where he needs to be to play at the peak level.
“So we have got to trust him, respect his decision and give him that support to get back to that top level.
“You want to represent your country and play as many games as you can.
“It’s not so much that he doesn’t want to play. He’s been here before and knows what it takes to play at international level, but he’s just slightly off that level he feels he needs to be at to play.
“It’s not a question of his desire or anything like that to play for Scotland. It’s just in this moment he’s not at that peak level.
“When you go into international football it’s another step up from your club stuff. You have to be right physically and mentally. You have to put those demands on yourself and if you’re not there you quickly get found out.”
While Griffiths will not be on the flight to Israel, there will be a familiar face in the opposition line-up at the Sammy Ofer Stadium for McGregor as he comes up against Moanes Dabour, just a week after the forward helped Red Bull Salzburg beat Celtic in a Europa League clash.
The Israelis have won just once in their last 10 games, but McGregor reckons the likes of Dabour mean they cannot be taken lightly.
“You can see many of their team are playing at a good level,” he said. “Last Thursday was saw the quality Dabour has got, so we are definitely not taking it for granted.
“The atmosphere over there as well means it’s a tough place to go and get a result.
“We’ve got to focus on what we’re doing this week and prepare as best we can to get something over there.
“We know if we can get three points we are in a real strong position.”