FREMANTLE small forward Michael Walters has received the green light from the match review panel for the opening round clash against Port Adelaide.

However, it’s not an all-clear for Freo's forward line, who could be without All-Australian selection Hayden Ballantyne due to a strained calf injury.

Walters was reported for misconduct after colliding with Swans player Craig Bird during the third quarter in Sunday’s NAB Cup match against Sydney.

After assessing the Swans’ medical report, speaking with the umpire and checking video evidence, the AFL Match Panel Review today decided it wasn’t a reportable offence.

Fremantle senior coach Ross Lyon said he’s concerned Ballantyne may not be in shape for round one against Port Adelaide.

The small forward experienced some calf soreness during the same NAB Cup match, and may sit out the Round 1 game if it’s strained.

Lyon also pointed to a tightened hamstring for Tendai Mzungu as another concern for the season’s opening.

"We've got a couple of little concerns," Lyon said.

"(Tendai) Mzungu tightened up in the hamstring so I think he'll be OK, but Ballantyne looks like he’s hurt a calf so that's a concern.

"If it is, he’ll probably miss round one, so that's not ideal."

Port Adelaide will take on Fremantle in Round 1 on April 5 at Patersons Stadium in Perth.