Smalling is looking for his second run-out for the club against Philadelphia Union on Wednesday at Lincoln Financial Field.
Smalling said: "The tour has been a really enjoyable experience so far. It was great to meet everyone, initially at Carrington.
"I have spent quite a bit of time with Wes and Jonny, my fellow centre-backs.
"And I have also been chatting to a lot of the younger lads. It is just great to get to know everybody and be part of such a great club. I just want to do my best."
Brown, now one of the United's senior players at 30, believes Smalling has a bright future.
"Chris is a great lad and has fitted in brilliantly," he said.
"He has been training really well - he looks very fit and sharp. I am sure he will be ready and raring to go for the start of the season."