The athletic midfielder has trained pretty much throughout the summer without playing games as a member of the England party in Germany, resulting in little fitness being lost over the course of the close season.
"It is coming back, I had a short break and it was nice to get out there with the first team again," said JJ after the 1-1 draw at the Westfalenstadion.
"I haven't lost much and it is a case of not over-working me, just making sure I am doing enough to get strong for the start of the season.
"I think I am more or less there, I played 60-65 minutes against Dortmund in what was a good level game so I am happy.
"Preparations are going really well for the team and I think we are as on course as we can be to try and get a good start to the season," he reasoned, before reporting that the hamstring problem that kept him out of the Spurs XI game against Cambridge City last weekend proved only a minor setback.
"It was a little one but I am fine now and it has all cleared up."
Jermaine Jenas featured in his opening First Team fixture of the pre-season programme against Dortmund and believes he is not far away from Premiership readiness.