"There's been a lot of personnel changes at the Highlanders so it's hard for me to say too much, but I'd feel uncomfortable to be honest saying too much,'' he said.
"But it's a team I've played almost 60 games for so I don't think I'd feel right. At least I'll know a lot [if I get on] and it was quite interesting sitting in the planning meeting today listening to how they perceive the Highlanders and how best to attack them.''
Rutledge, a plumber, had been working full-time before his call-up, but had been training with Southland. He had not been picked up by a Super Rugby side or wider training group.
"The Southland boys have been training pretty hard back home. I may be a little off the pace, but I can't imagine I'll be playing 80 minutes or anything. If I get out there for any amount of time I'm sure I'll be fit enough.''
Matu'u, who damaged an AC joint, is still a possibility to play in Dunedin on Friday night.
If he fails a fitness test, Hawke's Bay player Ash Dixon will wear the No2 jersey, with Rutledge on the reserves bench.
Hammett, a former hooker, said he had a lot of faith in Rutledge.
"It's great to be able to get Jason,'' Hammett said. "He's a quality character. He's already learned what he needs to and he only got here at 8.30 this morning. He's experienced, he's been around a long time. He's not the new boy.''
Coles could be sidelined for two to four weeks, Hammett said.
