Hibernian defender Ryan Porteous admits his first experience with the senior Scotland squad was an eye-opener.
The 20-year-old was promoted from the under-21 squad for last month's double header against Cyprus and Kazakhstan after Steve Clarke suffered a number of call-offs to his squad.
The centre-back did not feature in the games but reaped the benefits of training with former Hibs team-mate John McGinn and other Premier League players.
"It was brilliant, a great experience," said Porteous ahead of Sunday's trip to Celtic Park. "It was a real eye-opener to me of the standard you have got to get to if you want to play to the highest level.
"There were some great players there and to even train with them for a week and be around them every day was really valuable for me.
"Maybe it's just because you are away with Scotland and you need to impress the manager with the two games coming up, but it was 100 miles an hour and done to a real quality as well.
"Speaking to John when I was rooming with him, he said it was like that every single day when he is down at Villa.
"So that's the standard you need to get to, you need to set benchmarks for yourself in training and in games."
Hibs have recorded three wins in five matches under Jack Ross and Porteous is looking to continue the momentum against the Ladbrokes Premiership champions.
"He has not really had that much time to change much because we had that many games coming up," he said. "We have just got to be focusing on playing the games and getting results.
"Things are going well for us right now and I think we have just got to keep doing what we are doing and not think too much about Celtic because we know if they play to their full strengths that they are going to be a really, really tough team to take points off.
"You have got to hope they have an off day and that we do well. We will focus on ourselves."
