The Kiwi, who will lead the Lions for a second time when they tour New Zealand in the summer, has been in Edinburgh this week and said there was “no comparison” with the quality he witnessed compared with a similar trip he made ahead of the 2013 tour to Australia.
Scotland have won two out of three of their Six Nations games this season and go into Saturday’s Calcutta Cup clash at Twickenham dreaming of a Triple Crown and possible championship tilt.
Gatland said: “I was really impressed. There was no comparison with what I saw four years ago, in terms of structure, organisation, intensity, the way the session was run.
“Just from yesterday’s session, you could see why Scotland are improved. When a team are competitive and hard to beat, you can see that in a training session – and I saw that.”
Gatland was at Scotland’s Oriam training base before visiting the Cure Parkinson’s Trust, which is based at Edinburgh’s Royal Infirmary and is one of the Lions’ chosen charities.