Gatland says the All Blacks illegally targeted Murray during the Lions' 30-15 first Test defeat in Auckland and could have caused a career-ending injury.
"What he's implying is we are deliberately going out to injure somebody, and that's not the case. I guess he might be a bit desperate," said Hansen.
The Lions face Super Rugby champions the Hurricanes at Wellington's Westpac Stadium on Tuesday, with the second match of the three-Test series at the same venue on Saturday.
Gatland said New Zealand dived "blindly" at Murray's standing leg whenever he launched a box kick in Auckland.
He will seek discussions with the second Test's referee, Jerome Garces.
"I thought that was a little bit dangerous, and after he's kicked he's been pushed a few times, and pushed to the ground," said Gatland.
But Hansen said on Radio Sport NZ: "It's just really, really disappointing to hear him say that, and take the gloss off not only the Test match but from his own team's performance as well.
"As a New Zealander, I would expect him to know the New Zealand psyche. It's about playing hard and fair.
"We are trying to charge the kick down, and/or tackle him. Both those things are legal.
"Just because he is one of their key players, it doesn't mean to say he has a right to go around the park without being charged down or tackled."
After the game, Gatland said the All Blacks played a "very direct" style, which he believes would have been criticised if used by the Lions.
"It's another predictable comment coming from Gats," said Hansen. "He is looking to take the heat off his own team."
Gatland is set to bring flanker Sam Warburton and lock Maro Itoje into the starting XV for the second Test after the Lions were physically dominated in the series opener.
Tour captain Warburton and Itoje impressed as second-half replacements in Auckland.
Gatland said: "We might have to shake it up a little bit.
"Someone like Maro Itoje made an impact coming off the bench and was very physical.
"Sam Warburton was excellent as well at the breakdown when he came on."
Former Lions and England coach Clive Woodward said on Sunday that the Lions should change tactics rather than personnel as they attempt to win the final two Tests.
"We didn't lose the game based on selection," he told BBC 5 live's Sportsweek.
British and Irish Lions coach Warren Gatland's comments about New Zealand's treatment of Lions scrum-half Conor Murray are "desperate", says All Blacks boss Steve Hansen.