Wood suffered a broken foot during the derby-day defeat to Leicester Tigers.
The back row forward posted pictures of his injury on social media last weekend and Boyd has now confirmed that he will miss the trip to Sale.
When asked whether he had an idea how long Wood would be out for, Boyd said: "Not really, but it's not days."
Saints have received some welcome news from the England camp though, as club captain Lewis Ludlam and full-back Tommy Freeman have been released by Eddie Jones.
Courtney Lawes, Alex Mitchell and George Furbank remain with the Red Rose ahead of the Autumn Nations Series opener against Tonga this weekend.
Boyd said: "On one side it says we've got players of international quality, some are tier one and some are tier two, but they're all international players playing for their country, which is great and we support it.
"But on top of injuries it does challenge your squad, and it's going to be a big day for us on Saturday.
"We've got Dan Biggar with Wales, Nick Auterac with Scotland and then Sam Matavesi and Api Ratuniyarawa away with Fiji.
"Frank Lomani is still around this week because he's got a visa issue but he'll either leave before the weekend or after, depending on when his visa gets sorted out."
With Mitchell and Lomani potentially both away, Saints could be very light at scrum-half, but Boyd has confirmed that Tom James is now available to make his first appearance of the season.
However, more bad news comes in the form of Taqele Naiyaravoro and Ahsee Tuala, who have 'long-term' injuries.
"Both Taqele and Ace are long term so we won't see them in the near future," Boyd said.
"Taqele's had an ongoing problem with his knee, which will probably require surgical intervention.
"We won't see him any time soon.
"Ace has been carrying a chronic knee injury so he's had some intervention in the past couple of days and we'll see him on the other side of the PRC (Premiership Rugby Cup) hopefully."
Ollie Sleightholme remains sidelined after suffering a hamstring injury at Wasps last month, but Piers Francis, who was forced off after failing a head injury assessment during the same game, could return.
"Piers is there or thereabouts," Boyd said.
"Ollie is a bit longer term. We won't see him for four or five weeks."
Saints could opt to call upon summer signings Brandon Nansen and Karl Wilkins, who have been getting game time at Bedford Blues in recent weeks.
"They've both had games thanks to our relationship with Bedford, which has been really good for them," Boyd said.
"With Tom Wood' s injury as well, with his broken foot, those guys potentially have an opportunity to feature."
Another injury problem surrounds Matt Proctor, who returned from a hand issue to face Leicester last weekend but took a blow to the head during the game.
"We're pretty cautious on the HIA protocols and he's symptom free now but we'll play that one by ear," Boyd said.