Garry Monk was left to rue Ki Sung-yueng's disallowed first-half effort as Sunderland held Swansea to a 1-1 Premier League draw at the Liberty Stadium on Saturday.
Ki was flagged for offside moments before Jermain Defoe fired Sunderland into a 42nd-minute lead, and though the midfielder equalised in the second-half with a diving header, Monk was frustrated with his side failing to make their chances pay.
Monk joked the offside decision against Ki was so tight that he would order South Korean to get his hair cut, saying: "I was told his hairline was offside, although I am not sure that is part of the rules.
"Our cameras mean you do not get close ups of things like that so I will need to have another look -- but I will have to tell Ki to cut his hair!
"It's one of those where sometimes you get them, sometimes you don't. We have had a few like that this season."
Monk felt Swansea created enough chances to win, but said his side were punished for switching off and giving Black Cats striker Defoe time to open the scoring.
"It was frustrating as they scored from their only shot when we gave Defoe too much space," he added.
"We did not close it down and we got done, which set us back. We got a good equaliser, tried to push for the second and I felt we were the better team, but it was not to be."
Information from the Press Association was used in this report.