Swansea City head coach Francesco Guidolin admits his team's defending from set pieces is a "problem" they must address.
Saturday's 1-1 draw with Crystal Palace saw the Swans concede from a corner for a third game in succession.
The result leaves Guidolin's side 16th in the Premier League table and four points above the relegation zone.
"It is a problem at the moment - we must understand what is better for our team," he said.
"Don't be worried because, if a team is worried, it's negative. I think we have to look at the problems, to try to improve it but there is no need to be worried.
"We have to do more work on the training ground but it is not easy because it is different in matches - but we do need to work. We could have had two wins."
Scott Dann's equaliser for Palace came four days after Salomon Rondon also bundled in from a corner to salvage a 1-1 draw for West Brom against Swansea.
Although the Swans squandered a lead for a second successive match, they remain unbeaten in their four matches since Guidolin was appointed in January.
The former Udinese and Monaco manager rated the performance against Palace as Swansea's best since he took charge, but the 60-year-old Italian was frustrated not to win.
"This is the best game in my period," Guidolin added.
"The table is better than three weeks ago but we must take points every match.
"This is one point, which is not good because I thought we deserved to win."