Leigh Griffiths is "brave" to opt out of the Scotland squad, says Celtic team-mate Scott Brown, who wishes he had done the same more often.

Striker Griffiths is missing the double-header with Israel and Portugal to work on his fitness.

"Scotland and Celtic need Leigh as fit as he possibly can be for the whole season," said Brown, who retired from international duty in February.

"I think he's probably done the best thing for him for now."

Griffiths, 28, who has four goals in 19 Scotland appearances, was dropped to the bench for last month's win over Albania.

But coach Peter Grant insists there is "no issue" between head coach Alex McLeish and the centre forward.

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"It's brave of the wee man to have done that because he wants to work on his fitness," Celtic captain Brown said. "He wants to come in here and do better.

"Maybe going away with Scotland, he wouldn't have got the game time that he expected. The training wouldn't have been as hard with the two games coming up.

"If he can get himself as sharp as possible then he becomes the best striker in Scotland by far. He and Alex spoke and I think they've dealt with the situation quite well.

"Leigh will go on and have a great Scotland career, but I think it's time for him to work on his fitness. He says he's not feeling his best and he wants to get back to that."

'I should have been braver'

Brown announced his intention to retire from internationals in the summer of 2016 but was quickly persuaded to return after missing three games.

The 33-year-old then quit for a second time, having won 55 caps, following talks with McLeish, who succeeded Gordon Strachan as team boss.

"I should have been braver and sat out a couple of games and tried to get myself as fit as possible instead of playing through a couple of injuries," Brown said.

"You're always going to get a bit of flak, that's part and parcel of the job.

"I'm happy with what I've done for Scotland. I think I retired at the right time because new lads are coming through and they seem to be doing well and John McGinn has filled that position very well."

Brown has missed Celtic's last two matches with a hamstring injury but said he should be available for the next game at home to Hibs on Saturday, 20 October.