Defoe has been linked with Tottenham and Adams said: "Defoe wasn't dropped, of course not. I will make tactical decisions, technical decisions and emotional decisions. This time it was a tactical one.
"I want Jermain to be the top goalscorer for Portsmouth, he will be. I want him to be top scorer in the league and I think he can.
"But against the league leaders I wanted something different. We have been getting smashed up away from home, we have lost 3-0 at Braga, 6-0 at Manchester City.
"I felt we needed to be resilient and hard to beat first time out for me. That is why Jermain was rested.
"Jermain took it fine, he is 100 per cent behind me. I have had great support from everybody, but particularly from Defoe.
"I am a big fan of Defoe, maybe it was crazy to keep him on the bench for so long, but next time out it will be different."
He added: "Next time it may be Crouch left out, who knows. We have Wigan at home on Saturday and maybe they will both play."