Sherwin scored five tries during his time with Castleford
Scrum-half Brent Sherwin has left Castleford for Catalans Dragons, with the Tigers signing Huddersfield Giants' Kyle Wood on a one-month loan deal.
Sherwin, 32, joined the Tigers in 2008 and went on to make 52 appearances for the club.
Tigers chief executive Richard Wright said: "Brent wasn't in our plans for 2011 so the timing was right. Brent leaves with our best wishes.
"We have brought in an immediate replacement in Kyle Wood."
Wright added: "We will be exploring other options over the next couple of weeks.
"Kyle is a highly-regarded, exciting young player who is keen to make his mark in Super League."
Half-back Wood, 20, has played for Wakefield and Sheffield and had a spell with Batley Bulldogs this season.
Former Canterbury Bulldog Sherwin has joined Catalans for the rest of the season.
He said: "I am hoping to play another season in Europe before returning home to Australia so I'll be doing my very best to win a longer deal with the Dragons."