The Magpies captain was an unused substitute against the Hammers with Emil Krafth handed a surprise start instead.
Lascelles watched on as his teammates shipped three second-half goals having led 2-1 at half-time.
Bruce missed the presence of his captain in the backline but felt he had no choice but to leave him out due to his fitness levels.
Lascelles missed the remaining eight games of last season after undergoing surgery on his foot.
"Jamaal has had a difficult pre-season," Bruce said. “He’s just getting over an operation and obviously he needs minutes.
“It’s been a toil for him, which is understandable. I just thought, physically wise, that was the best bet.
“With another week, or ten days or so of training, hopefully we’ll see the return of the captain.”
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