Jetta has played all 11 games to date in his first season, but Roos said the speedy West Australian had shown signs of fatigue in recent weeks.
Jetta is joined by Henry Playfair in the list of omissions, with the Swans welcoming Tadhg Kennelly and Ben McGlynn back from their respective knee and quad injuries.
Speaking before the Swans trained on Thursday evening, Roos said Jetta had taken the news of his omission well.
“I think they’re pretty aware of where they’re at. It was probably only after we explained it to him that he said, ‘yeah, I am feeling a bit tired’,” he said.
“They all love to play but what you’re trying to do as a coach is use your experience a little bit and your knowledge of where they’ve come from and where they’re going.
“It’s a big effort to play all 11 games and to play the way that he has… with the energy that he plays with, we knew that at some point, potentially we might have to give him a spell.”
Jetta will play with the Swans’ reserves in Canberra this weekend and Roos expected him to enjoy playing without the added pressure of senior footy.
“Releasing the pressure just a little bit gives them a chance to go back and play and have fun, and not worry too much,” he said.
“It’s in Canberra so not too many people will watch him play and it’s a bit of getting back to enjoying his football. We’ll have him back in the senior team pretty quickly.”
In contrast, Playfair will have a break from all football to rest his surgically repaired hamstring.
The big forward has played the past four games after missing the entire 2009 season with a chronic hamstring complaint and Roos said Playfair admitted to some soreness in the area after the round-11 win against Essendon.
Rather than risk another injury, the Swans opted to rest the former Cat and ensure his fitness for the second half of the season.
The return of the lively McGlynn should prove an adequate replacement for Playfair, despite the two playing vastly different roles in the forward line.
Roos said he didn’t expect McGlynn to reprise his five-goal performance from the Swans’ round-two win against Adelaide at AAMI Stadium but he said the former Hawk was ready play a significant role.
“He’s not going to be absolutely back to his best … but [playing] again this week and having a week off gives him a really good chance to play well in the back half of the season,” he said.
“He’s a smart player, a really dangerous player. He runs really well and it’s a big ground at AAMI, so he’s certainly a player you love having back in the team.”
Roos also confirmed that key forward Daniel Bradshaw had resumed running after his second bout of knee surgery and was on track to return in the Swans’ round-13 clash against Collingwood at ANZ Stadium.
