(REUTERS) - Manchester United manager Ole Gunnar Solskjaer said he has been informed by the refereeing body Professional Game Match Officials Board (PGMOL) that two costly errors were made by match officials during their 2-1 Premier League defeat by Sheffield United last week.

Solskjaer said the independent report as part of the match assessment by PGMOL revealed that Kean Bryan's opening goal for Sheffield United should have been chalked off for a foul on goalkeeper David de Gea.

Meanwhile, United forward Anthony Martial's goal was wrongly disallowed at the other end.

"The momentum shifted for us with the Sheffield United game, but I've got the delegates' report from the ref and the two decisions were wrong," Solskjaer told a news conference on Monday (Feb 1).

"They've admitted their goal should have been disallowed and our goal should have stood. That's a big, big momentum changer for us. When you go 1-0 up rather than 1-0 down, go on and win that game."

The defeat against Sheffield United followed by a 0-0 draw at Arsenal on the weekend left United three points behind leaders Manchester City, who have a game in hand.

United are looking to bounce back against Southampton at Old Trafford on Tuesday, with Solskjaer hoping his attackers rediscover their mojo after firing blanks at the Emirates Stadium on Saturday.

"We created enough chances to score the goals now it's about feeling good, taking a deep breath and putting the ball between the posts," he added.

He said United will not be making any signings before the transfer deadline on Monday.

Phil Jones is yet to play a game this season due to injury but Solskjaer said the centreback will stay at Old Trafford and be registered in United's Premier League and European squads for the second half of the season.