A dreadful first-half display saw the Shropshire side go in at the break 3-0 down during their Midland League Premier Division clash. After receiving the hairdryer treatment from Carrier and fellow joint-boss Danny Carter, they battled their way back to 3-2 thanks to goals from Tom Hill and Kyle Montague.
But Romulus held on to get the win despite Keanu Cooper hitting the bar for Shifnal.
“The mentality wasn’t there on Saturday,” Carrier said. “We’re a new team in this league and we have learnt so much since the start of the season.
“But we backed off in that first-half.
“The players got the hairdryer treatment at half-time because it wasn’t a football thing, it was a mentality thing.
“It was about competing in the right way. We told them to grow a pair.
“We’ve come a long way but the Romulus game was a lesson that we have to be competitive and win first and second balls every week.
“If you don’t do that, if you stand off in this league you’ll be punished.”
Elsewhere in the division, Haughmond were beaten 3-1 at home by Stourport Swifts with Joseph Yeboah netting their consolation.
Whitchurch Alport were not in action over the weekend.
In Division One, AFC Bridgnorth secured a 2-1 win at Heath Hayes thanks to goals from Kevin Buxton and Nathan Derrick.
Meanwhile, Shawbury United beat Coventry Copsewood by the same scoreline.
In Division One South of the North West Counties League, an 87th-minute goal from Steven Hole saw Ellesmere Rangers secure a point in a 3-3 draw with Cheadle Heath Nomads. Rangers took the lead through Ryan Morgan but they fell 2-1 and 3-2 behind with Hole equalising both times.
It was another miserable weekend for St Martins, who were beaten 7-0 at Maine Road.