It was not a good day at the office for Newcastle who suffered a 3-0 defeat at St James' Park, with full-backs Jetro Willems and Javier Manquillo being forced off with injuries during the first half, while midfielder Jonjo Shelvey had to be replaced at the break.
That meant Bruce had to use all of his substitutes before the second half got underway and, 10 minutes after the restart, the Magpies also lost defender Fabian Schar to an apparent hamstring injury and so had to play the rest of the contest a player short.
DeAndre Yedlin, who had earlier replaced Willems, also went on to suffer a broken hand although he was able to soldier on through the rest of the match.
However, Bruce was not only left counting the cost of a third successive Premier League defeat but also had to come to terms with losing five players to injury, although he was quick to point out what he felt was to blame.
"You get injuries by forcing players to play tired. That's not an excuse, it's a fact. I was concerned before the match, I made that clear," the 59-year-old told reporters.
"You don't want it to happen that way. It could have been five we lost because Yedlin broke his hand, he manfully played on. In all the years I've been involved, I don't think I've been involved in a crazy 15 minutes like that.
"I said it a month ago that, to ask players to play four games in 10 days is ludicrous. Today is the consequence."
Newcastle already had a lengthy list of absentees as captain Jamaal Lascelles, Matt Ritchie, Paul Dummett, Ciaran Clark, Sung-Yueng Ki and Allan Saint-Maximin all missed the defeat to Leicester through injury.
That leaves Bruce with limited options ahead of Saturday's FA Cup third-round trip to League One Rochdale and, with league matches on the horizon against Wolves, Chelsea and Everton, the former Aston Villa boss will be hoping some of his stricken stars will be able to return sooner rather than later.