Michael Carrick admitted Manchester United have to improve their set-piece marking after conceding two goals from corners in their 3-1 defeat to Chelsea on Sunday.
Samuel Eto’o scored a hat trick for Jose Mourinho’s side and the Cameroonian’s second goal came when United defenders lost him after half-clearing a corner.
The striker’s third followed when Gary Cahill escaped from Jonny Evans to meet Willian’s corner and, after David de Gea saved, Eto’o scored the rebound.
Manchester City’s Yaya Toure, Southampton’s Adam Lallana, Cardiff’s Kim Bo-Kyung and Hull’s James Chester have all profited from poor set-piece marking to score against United from free kicks or corners this season.
Manager David Moyes said “terrible defending” cost United at Stamford Bridge and Carrick concurred, telling MUTV: "We have to defend better from set pieces. From open play they didn’t look that dangerous -- we didn’t feel they were much of a threat.
"But we need to create more ourselves. Even after getting one back to give ourselves a sniff, we couldn’t create that opportunity to get one more."
The England international was disappointed with both the timing and the manner of Chelsea’s second and third goals, which came in the 45th and the 49th minute respectively.
He added: "The end of the first half killed us. I thought we were the better team for large periods of the first half, so to find ourselves 2-0 down was a blow. We said at half-time that if we got the next goal, we’d be right in the game, but it was an uphill task when the third one went in. Both those goals came at bad times and, at this level, they shape the game."