The 26-year-old Sears has 58 first class wickets from his 19 appearances at an average of 27.
Black Caps coach Gary Stead said Sears was ready for test cricket.
“Ben’s a young bowler with a quality skill set,” he said.
“He bowls with genuine pace and gets good bounce which is always a great asset in red ball cricket.
“We’ve been really impressed by his performances for the Black Caps in white ball cricket this summer and believe he can make the step up to the test arena if called upon.
“It’s disappointing for Will to be ruled out, especially after making such a strong start to his international career.
“He’s shown he’s a player with huge potential and at 22 years old we’re hopeful we will see a lot more of him in the Black Cap.”