How to assign name to intermediate whilst pattern matching in Scala

I'm doing some pattern matching on a colon delimited String as follows:

case s:String => s.split(":") match {
  case Array("foo","bar") => ...
  case Array("hello",_,_) => ...
  ...
}

How can I rearrange the code to assign a name to the array returned by s.split(":")?

I've tried the following to no avail:

case s:String => val x = s.split(":") match {
  case Array("foo","bar") => // try to use x here
  ...
}