That defeat came as a shock to the system after our bright start to the season and Kasey is determined to bury it at the Riverside on Saturday.
"They've had a fairly similar season to us," said our super stopper of Steve McClaren's outfit. "They've done very well at times but then let it slip and that's why we're only a few points apart.
"They have some very good players and want to take that next step up. They are a big club with good support in a big football area.
"It's a tough test and we played so terrible against them at home as well that we perhaps owe them a little.
"Juninho will be there and he's obviously trying to prove some things afer missing most of the season with a knee injury.
"We'll be smarting from United and now it's all about trying to show the manager that you are the guy for next season."
Kasey Keller reckons we owe Middlesbrough one after the Teesiders beat us 3-0 at the Lane back in September.