Wilshere is missing from this week's England squad.
"Since Jack has come back, he has been outstanding. He has performed to an amazing standard," Oxlade-Chamberlain told PA Sport.
"For Jack, the injury he had, he learned a lot from that, he grew as a player and a person, to get back from that 18 months out has really shaped him, he is a dedicated professional - the preparation he puts in not to get injured in the future is amazing.
"He is the first one in training and near enough the last one out, doing extra rehab. He works so far to make sure he stays fit and it has worked well for him.
"Jack is a really good lad, maybe he comes across a bit shy, but he is really dedicated and focused on what he has to do."