With flanker James Haskell serving the first match of a three-week ban for striking in the Highlanders' win over the Cheetahs last weekend, Joseph is short of loose forwards.
Tietjens, wearing the No7 jersey which Haskell has served well this season, went off with a suspected ruptured knee cruciate ligament. His replacement, Dixon, lasted only about 10 minutes before he joined him on the sideline with a ruptured pectoral muscle. Treeby has a suspected fractured cheekbone.
The Highlanders arrive back from South Africa on Tuesday night and must quickly turn things around in preparation for the Hurricanes in Dunedin on Saturday. The men from Wellington got things back on track after two losses with a convincing 35-19 over the Blues in the capital on Friday night.
"We tried to hold on to the ball for long periods of time but got caught in our half," Mackintosh said. "We had opportunities to win that game and put pressure on them but to their credit they defended and matched us at ruck time and it was a pretty good game."
The Sharks went to the break 15-9 up, with Joseph bemoaning the slow start by his side.
"It was 12-3 and we hadn't even thrown a punch, so that was a wee bit disappointing," he said.
"I guess you put that down to a tenacious and committed Sharks side that didn't give us an opportunity."
While Mike Delany struggled to find his range in the first half, missing two relatively easy kicks, opposite Patrick Lambie couldn't miss and the Springbok scored all of his side's points with a try, conversion and seven penalties.
The Hurricanes, confidence intact again after their five-try mauling of the hapless Blues, will fancy their chances of beating the Highlanders on Saturday night.
The clash of the young halfbacks will be fascinating, with Highlander Aaron Smith up against TJ Perenara who starred in Wellington with his evasiveness and ball skills.
Perenara, 19, scored a second-half try against the Blues and completely outplayed his former mentor Piri Weepu. Another former Hurricane, Ma'a Nonu, was also disappointing for the Blues.
Pat Lam's men will be eyeing the clash against the Lions at Eden Park on Friday as their big chance to double their win tally for the season but will find the Lions, coached by former All Black John Mitchell, tough opponents to crack.
They lack a lot of talent outside their first-five Elton Jantjies, but have a huge pack which caused the Chiefs a few problems last night. Captain Joshua Strauss is an inspirational figure at No8.
Although the Chiefs predictably scored a bonus point 34-21 victory, they were troubled at times, with the Lions scoring three forward-based tries almost without breaking sweat.
With Jantjies also kicking for goal well, the Lions could have caused more problems if they had played for territory rather than running everything which resulted in inevitable mistakes and turnovers.
The Chiefs' pack, missing loose forward Liam Messam with a rib injury and prop Sona Taumalolo starting from the reserves bench, didn't convince as much as in recent matches. However, the good form of second-five Sonny Bill Williams and centre Richard Kahui, who left the field briefly with another facial injury, continues.
The Chiefs next week travel to Brisbane to play the Reds.
In Melbourne on Friday night, the Bulls beat the Rebels 41-35, both teams scoring four tries in the first half. The Cheetahs beat the Force 17-13 in Bloemfontein last night. The Brumbies tightened their grip on first place in the Australian conference with a 23-6 win over the Waratahs.
