STAR West Coast forward Jack Darling has avoided a long spell on the sidelines but will be out of action for between four-to-six weeks after suffering a hairline fracture and ligament damage to his ankle against St Kilda.

Darling looked in serious trouble when he crumpled to the ground after landing on Saints defender Logan Austin's foot in a marking contest during the first term of Saturday night's 13-point win at Optus Stadium. 

"After initially fearing the worst, we’ve received some reasonably positive news from our doctors, all things considered," general manager of football Craig Vozzo said. 

"He’ll be out for probably a four-to-six-week period, so factoring in the bye he hopefully won’t miss too much football.

"Jack is a real professional in how he approaches all facets of his football, so we’ve got every confidence that’ll he’ll be back sooner rather than later." 

While the 25-year-old's injury is not as severe as initially suspected, it is still a blow for the League-leading Eagles, who face a tough stretch after their bye.  

West Coast travels to take on top-four rival Sydney next before facing Essendon (Optus), the Crows (Adelaide Oval), Giants (Optus) and Collingwood (MCG).

Darling's career-best form has been a major factor in West Coast's surge to 10-straight wins, with the maturing big man sitting third in the Coleman Medal race (28 goals) and leading the competition for contested marks (31).  

The Eagles could turn to their top pick in last year's NAB AFL Draft, mobile tall Jarrod Brander, to replace Darling.  

However, high-flying Liam Ryan is also a chance to return against the Swans after his long-term ankle injury and West Coast could field a smaller forward line with Jake Waterman shuffled into a role as a tall marking target. 

Speaking after the Saints win, coach Adam Simpson said the Eagles would rely heavily on spearhead Josh Kennedy to cover Darling's loss.

Kennedy bagged six goals in a match-winning display against St Kilda and is building his form after pre-season ankle surgery.

"He missed all pre-season, so we've been really cautious about his minutes and I'm really glad he's getting more and more like himself," Simpson said.

"Jack's been holding up his end of the bargain with JK coming back. Now we're going to have to lean on Josh."