Gatland believes the English lock and blindside flanker will be one player the All Blacks will have a special focus on in the three match series starting June 24.
Itoje has been impressive for England since making his test debut last February, winning the World Rugby Breakthrough Player of the Year award last year.
The All Blacks have yet to face off against Itoje who captained England to the 2014 IRB Junior World Championship in Auckland.
"He could be a player they may target, and I'll be interested to see how he responds to that," Gatland told the Telegraph newspaper.
"They might see him as potentially a key for the Lions and see if they can shut him down, or physically dominate him.
"He's going to have to learn from that."
The Saracens player has all the physical attributions but will inexperience, with just 12 tests to his name may be his downfall during the Lions tour, coming across the likes of Kieran Read (97 tests), Sam Whitelock (84) and Jerome Kaino (77).
Gatland believes the six-foot-five Itoje is only going to get better but will have to play smart rugby in New Zealand.
"The more he plays the better he's going to get. He's got a massive engine on him and his work-rate is just phenomenal," Gatland added.
"Hopefully we can get him to play a little bit smarter in terms of picking his moments, with that youthful enthusiasm of trying all the time.
"He's just involved in everything. Just looking at him, he will respond to that challenge."