England hooker Hartley was a surprise inclusion in the 37-man squad named on Tuesday for the tour to Australia, securing a place ahead of Rory Best who was expected to be included.
In the build up to the 2011 6 Nations, Wales scrum-half Richie Rees was banned for 12 weeks for gouging Hartley, prompting Gatland to criticise the Northampton front row. But Gatland insists the hatchet has been buried and is looking forward to working with Hartley, saying: "I've got a lot of respect and time for Dylan, despite what people might think."
He added: "I don't want to raise the issue, but I made the comments that I made because of the way in which Dylan was advised to speak about how a player was suspended and that upset me.
"The reaction didn't really fit for me - a tough front row forward and a Kiwi boy brought up in Rotorua. If someone grabs you by the eye and you don't have a reaction, yet it's so painful afterwards......
"I said the things I did. Afterwards I went up to him, shook his hand and told him I was a little bit over the top in what I said. He respected that. His form has been good recently, but Rory Best was really unlucky."
Gatland insists the Lions must be ready for "psychological warfare" in Australia, claiming the media will be used as a platform for mind games.
"Part of our job is to cover off every eventuality - psychological warfare in terms of the media and what people might say because that's what happens in professional sport," he said.
"The media can potentially have an influence on young men and players and we must guard against ourselves and be prepared for what might happen in Australia.
"The great thing about Australians is their desire to win. They're incredibly competitive and we have to be prepared for anything, media wise or anything from coaches or former players."
- Sports & Recreation