COLLINGWOOD midfielder Tom Phillips is battling a mystery ailment a week out from the Magpies' home preliminary final.

Late on Friday afternoon Phillips was spotted entering the Olympic Park Sports Medicine Centre.

The hard-running wingman then joined his teammates for the Pies' big training session of the week, but only ran laps at a leisurely pace alongside first-year players Isaac Quaynor (foot) and Will Kelly (hamstring).

The 23-year-old was a strong performer in the qualifying final win over Geelong, having 29 disposals, including a personal-best 24 kicks, and laying four tackles in an equal season-high 94 per cent game time as Collingwood's rotations were limited following first-half injuries to Jordan De Goey and Levi Greenwood.

At training on Tuesday morning Phillips seemed to complete the light skills session without issue.

The left-footer has enjoyed another consistent season, playing every game for the second season running while averaging 24 possessions and tallying 12 goals.

However, the Pies will be buoyed by the training efforts of James Aish, who appears set to replace Greenwood after overcoming a shoulder injury, and fellow defender Matt Scharenberg, who was omitted for the qualifying final.

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Veteran trio Travis Varcoe, Ben Reid and Daniel Wells also stepped up their bids for recalls, with Reid moving well up forward in match simulation while opposed to versatile tall Jordan Roughead.

Whether Roughead remains in defence or returns to attack is expected to have a considerable bearing on the Magpies' inclusions against the winner of Saturday night's semi-final at the Gabba between Brisbane and Greater Western Sydney.

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