Called up to replace Elliot Daly last week, Farrell took part in his first full training session with the Lions on Tuesday.
Itjoe – who took over from Jamie George as England captain before this year’s Six Nations – said he is excited about what the now four-time Lions tourist can bring to the table in Australia.
It is highly likely that Farrell, who can provide cover at fly-half and inside centre, will play against the AU-NZ Invitational side in Adelaide on Saturday.
It will be 10 weeks since he last played a game, having suffered a concussion with his former club Racing.
“It’s pretty exciting to see what he could potentially bring to us,” said Itoje.
“Owen and I actually went to the same school. When I was in Year 7, he was in Year 10 – so I’ve known Owen since I was literally 11.
“But he didn’t start talking to me until maybe I was 12 or so. The Year 10s didn’t really speak to the Year 7s. When I got to Year 8, he started to talk.
“I have a very good relationship with him. And he just wants the squad to do well. He’s obviously back at Saracens now, which is great.”
Itoje, who returns to the lions side for Wednesday’s game against the Brumbies, was also asked if he is bemused at the way people react to Farrell.
“It’s quite remarkable, really,” he said. “He does provoke pretty strong reactions, either way. It’s pretty crazy.
“I’m sure he’s thinking, like, ‘what did I do?’ But no, he’s fine, and I think everything will be cool.”
