Smith's wife, Kate Menzies, is due to give birth to their first child on the day of the game.
Joseph says Smith will be named on Thursday in the team, but there are no guarantees.
"It's one of those situations over which we have no control but we have a policy of family first," he said.
Wing Richard Buckman and flanker Shane Christie are still injured but first five-eighth Lima Sopoaga and midfielder Shaun Treeby will be available for selection again this week.
The Chiefs are fresh from belting the Crusaders 40-16 and Joseph is under no illusions about the Highlanders' task after their hard-earned 20-13 win over the Queensland Reds last weekend.
He described the Chiefs as the form team of the competition.
"They punished the Crusaders last weekend and that's a wake-up call for everyone," he said.
"Their off-loading ability, led by Sonny Bill Williams and Liam Messam, is a big threat. We need to make our tackles on Sonny Bill and deny him time and space."
Joseph said the Highlanders had to ensure they got enough territory and ball in hand at Waikato Stadium.
"Our skill level under pressure hasn't been great so far," he said.
"We need to make players accountable for the execution of their skill levels even though we may not have the depth of the Chiefs."
Joseph said his squad were looking forward to heading on the road after opening their season with two matches in Dunedin.
"There's been a lot of hype and distractions with the cricket World Cup," he said.
"Sometimes it's good to get out of town even though we love playing at the stadium."
