Former Perth Heat pitcher Liam Hendriks has been designated for assignment by the Oakland Athletics after a disappointing start to 2018.

After giving up nine earned runs in 11 innings to start the year, Hendriks was removed from the Athletics' 40-man roster ahead of their series with Warwick Saupold's Detroit Tigers.

Oakland now have 10 days to either trade or release the 29-year-old.

Athletics Manager Bob Melvin says it wasn't easy to part ways with the Australian.

"You've got to make a decision, and sometimes there's difficult ones," he said.

"That was the move that we made. We need a little bit more length down there with some of the guys that we have."

Melvin has confidence we haven't seen the last of Hendriks, however.

"Liam will get picked up somewhere," he said.

Hendriks joined Oakland via a trade from the Toronto Blue Jays in 2015 and has since amassed 136 games for the A's.

After starting his MLB career with the Minnesota Twins in 2011, Hendriks also had a stint with the Kansas City Royals in 2014 before finding a home in Oakland.

The former Sacred Heart student made his name in Perth, winning the Australian Baseball League Rookie of the Year for the Perth Heat in 2008 after pitching to a 3-0 record with a 1.90 ERA and 25 strikeouts.