Carlos Carvalhal is demanding a big defensive improvement from his Owls side after their frustrating draw at Burton Albion.
Gary Hooper’s first Championship goal of the season put Wednesday in charge at the Pirelli Stadium.
But the Owls were caught napping by a long throw-in and substitute Joe Mason punished the visitors, firing a right-foot shot through Tom Lees’ legs and past Joe Wildsmith.
Head coach Carvalhal told The Star: “It was a very strange goal and we can’t give goals away like that. We had the game in our hands.
“We lost concentration. It is something we must correct. It is things that happen in football but we must try to do better in the future.”
Carvalhal, who claimed Marvin Sordell should have been sent off in the first half after a heavy collision with Keiren Westwood, rued his side’s wastefulness in front of goal following a third draw in five league outings.
“I don’t know how we didn’t win the game,” he said. “We were the better team and I feel bad for our players.
“My players played with soul, were professional, compact and played with big discipline.
“We should have won the game.
“We scored one and then we created more chances to go two in front, but unfortunately the goal didn’t come.
“Their goal is one that we shouldn’t concede. They did not trouble our defence much during the game. The players are frustrated. I thought we deserved more than what we achieved and we did enough to win.”
Westwood was taken off after clashing with Sordell. The goalkeeper received six minutes of treatment and bravely tried to carry on but was eventually replaced by Joe Wildsmith.
Westwood left the ground wearing heavy strapping on his right leg and is a major injury doubt for the Republic of Ireland’s World Cup qualifiers against Georgia and Serbia. The 32-year-old has been capped 21 times by his country.
“I’m sure that if he came out (of the game) and it was a hard kick that he will have some days out of training,” conceded Carvalhal.