Gatland hinted in the aftermath of England's defeat to Ireland at the weekend that Hartley was in danger of missing the tour completely due to intense competition, despite skippering his nation to back-to-back Six Nations crowns.
Speaking to Sky Sports News on Monday evening, however, Gatland attempted to backtrack slightly when quizzed on the captaincy situation and admitted that the Northampton Saints ace is still in his thinking ahead of naming his 37-man squad on April 19.
"Look, he's done a fantastic. He's someone that's bounced back from a lot criticism and controversy," he said. "There's a lot being made of the sin bins, suspensions and the sendings off but I admire that way he's fronted up.
"I went and watched England train a couple of weeks ago and he came up and shook my hand and said 'welcome to training... I better not stay talking for too long because the boys are going to give me a bit of abuse for doing that', but you've got to take your hat off to what he's achieved as England captain.
"They've won back-to-back Grand Slams, they've been involved in that winning record in terms of the number of games. So, definitely, he's someone that we need to consider."