Things looked rosy on the South-Coast that day as goals from Gareth Bale and Clint Dempsey put us 2-0 up at half-time.
But the Saints were a different team in the second half, got a goal back through Jay Rodriguez and pushed us all the way.
"We had a difficult game there, we went 2-0 up but they scored early in the second half and it was tough," he recalled.
"We know what to expect and everyone is ready for Saturday."
Saints have impressed on their return to the top flight - they've won or drawn 21 of their 34 games so far to sit 13th in he table.
Rodriguez has hit form of late and Ricky Lambert has impressed with 14 goals so far.
"They are a strong side, they want to play football and they've had some amazing results, especially at home," added Jan.
That home form includes wins against City, Chelsea and Liverpool and draws with Arsenal and Everton.
"We have to be ready for another final on Saturday, like all the games," concluded Jan. "They are all important now."