Bruce expressed his surprise over Sherwood's departure which came shortly after Pepe Mel's exit from West Bromwich Albion on Monday night.
Bruce said: "I never thought I'd see the day but it's now becoming like it is in Europe or South America - in fact it's probably worse now.
"We keep getting told the average lifespan (for a manager) is 13 months and another good young manager has just lost his job.
"From the outside I don't know how much more he could have done. In terms of results he's been terrific.
"I've been in management for 15 years now and two or three people have lost their jobs in the last 48 hours so I'm going to take a deep breath and enjoy the occasion."
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