Tony Mowbray revealed goalscoring hero Roman Bednar was only a head injury away from being substituted before his last-gasp header secured Albion's first victory since early October.
The Baggies boss admitted Bednar was set to depart in the 83rd minute seconds before Manchester City scored their equaliser; however skipper Jonathan Greening was subbed due to blurred vision after a clash of heads.
In the end, Bednar supported Craig Beattie in attack and took advantage of static City defending to nod Albion just four points away from safety.
"There was a strange run of events leading up to that," Mowbray admitted at full-time.
"Originally, we were going to try and protect what we had, play one up front and spread out across midfield to stop them trying to play through us.
"But Jonno said he had double vision.
"A long throw-in was about to come into our box so it was the time to get him off.
"We wouldn't normally make a change when there is a set-play in our final third, but with Jonno struggling to see we made that change rather than bringing Roman off.
"Maybe it was a play of fate that Roman scored the winner in the 92nd minute.
"But I wouldn't put it past our team to do what they did.
"I know we can get the ball into good areas.
"We just struggle at times to finish things off.
"Roman made lots of intelligent runs and ultimately was still doing it in the 92nd minute to get the winner."
Before the Czech international's last minute winner, the former Hearts man had impressed up front along with Luke Moore, who also caught the eye and scored this first goal in a Baggies shirt.
Now, after the season-ending injury to Ishmael Miller, Mowbray is hoping the two can create a strike partnership which will fire the Baggies to safety.
"We're all delighted for Luke," Mowbray added.
"It's been difficult for him here and hopefully that's a monkey off his back.
"He's scored an important goal in a week when we've been talking about the transfer window and new strikers coming.
"That was maybe the spur both strikers needed to score.
"They stepped up to the plate and got the job done themselves. They both did great.
"Let's hope they continue to do that over the next few games.
"If we do bring new strikers in January, they could find themselves on the bench because the boys in the team are doing the job."