COACH Paul Roos says ruckman Mark Jamar took his omission from the team in a professional, team-oriented manner.

Jamar, who was left out for Saturday night’s clash against the Sydney Swans at the MCG, was replaced by Jake Spencer, who has dominated in the ruck for Casey in recent weeks.  

Roos said the telling nature of the ruck position simply forced the match committee’s hand after five rounds into the season.

“Mark was terrific in accepting that (his news),” he said at the MCG on Friday afternoon.

“He’s still a really important part [of the team], but it [really] is ruck by committee now, when you look at such a long year. It’s a tough year for those ruckman, when they’re generally just [playing] one out [by themselves] most weeks.”

Roos said playing in the ruck “a really tough role” in 2015.

“With that sub [rule], that used to be the second ruckman,” he said.

“I spoke to Mark this morning and said ‘we’re not unhappy with the way you’ve been playing, but it’s hard to do it week in, week out’.

“His concentration levels have got to be enormous – you’ve got to get to 80 or 90 stoppages, and then in between stoppages, you’ve got to be active.

“The other thing is that Jake has been playing really good football at the lower level.”