Johnson happy to be back at Portsmouth
The London-born defender said: "It was very disappointing the way we played at Arsenal until well into the second half. Then we got going a bit.
"By then, though, it was too late and a team like Arsenal always punish you if you are not at your best.
"I would have liked to have got forward a bit more but because it was my first game back I tried to ease my way in gradually. Getting forward is my strength, though, and I want to do that more when we play Liverpool."