Former Bay of Plenty No10 Dan Hollinshead has been whistled into the team and was due to join the squad yesterday.
Hollinshead, who played in the same national school team as Josh Ioane, hails from Tauranga and played for Bay of Plenty before leaving to play in Japan.
He has played for the Coca-Cola Red Sparks over the past couple of years. He played for the Chiefs development team but has not played Super Rugby.
Gatland injured his foot in the big win over the Sunwolves and is out of rugby for at least six months. He came on in Tokyo with 20 minutes left but departed the field with about 10 minutes to go.
Highlanders assistant coach Mark Hammett said the injury was disappointing for the young first five-eighth.
''It is a pretty major foot injury and he is out for the season. So that is the one big blight on the weekend,'' he said.
''I think he has broken at least two of his metatarsal bones, done ligaments and displaced something else. It's obviously not very good. I think he got his foot caught with another person.''
Hammett said Hollinshead would come in on a week-by-week basis which was dependent on how the fitness of Marty Banks was tracking. Utility Josh McKay was also an option.
Banks broke his foot in the match against the Hurricanes last month and was slowly tracking towards fitness but was unlikely to face the Chiefs this Saturday night at Forsyth Barr Stadium.
Hammett said the side was buoyed by the 52-0 win over the Sunwolves, which was a good performance
''You probably hear us harp on about week by week and that was no different for us. We wanted to get over there, and we did not change a lot, but we wanted to play with intensity and enthusiasm.
''It was nice to get none scored against us. That was a positive, one of them. We know that it was not perfect but the effort was exceptional.
''But you have to remember leading in we had that four-game losing streak so we were not far away. We were confident in our game and to be a bit more accountable around maintaining ball, and looking after it a bit more carefully.''
The Chiefs now arrive and Hammett said both sides were probably in the same space.
''They are desperate, we're desperate, and if you look at the table, it is very, very close.
''When we talk about desperate it's not around going out there and going into our shells. That is probably the worst thing we could have done. One thing we have done in the past couple of weeks is be a bit more expressive around our game.
''We have just tightened up the detail ... it does not mean tighten up this week but understand that both teams are going to be at their best energy-wise.''
Hammett said injured players Liam Squire, Waisake Naholo and Banks were unlikely this week but might be right to play the Jaguares next weekend. Whether they come back via club rugby will come down to the individual player.
The Chiefs will have to do without captain Brodie Retallick on Saturday as he is still out with a wrist injury.