Manchester City striker Sergio Aguero admits his side's hopes of retaining the Premier League title are looking a "bit grim" after their shock defeat against Southampton.
City produced one of their worst performances of the season in a 3-1 loss at St Mary's on Saturday, prompting manager Roberto Mancini to virtually concede the title to leaders Manchester United.
Mancini's second placed side will be 12 points behind United if Alex Ferguson's men beat Everton at Old Trafford on Sunday and Aguero acknowledged the situation looks bleak.
"Some days, nothing works the way it should," Aguero wrote on his Twitter account on Sunday.
"This was one of those days. There's no excuse - we need to work hard to forge ahead.
"It all looks a bit grim right now, but I won't believe giving up is an option."