HARRY McKay will return for Carlton on Friday night, with Blues coach Brendon Bolton shining a light on why the young forward has endured a prolonged absence from the team.

The 20-year-old's development amid a tough start to the season had been a rare positive for the Blues, with the 200cm forward kicking 12 goals from his first six matches this year.

However, he was left out of the side six weeks ago and hasn't been seen since, with his lack of senior appearances a constant talking point among fans during the past month.

But with ruckman Andrew Phillips suffering a season-ending hamstring injury last week and with fellow forward Matt Wright set to miss Friday night's clash with St Kilda due to soreness, McKay will get another opportunity to impress at Etihad Stadium.

"I'll give you the story of Harry McKay," Bolton told reporters on Thursday.

"Unfortunately, for two years – and he was already very young in his draft – he was hampered by a back injury … and then a significant turf toe injury.

"His first two years are practically a wipe-out in terms of training. He was then hampered into this pre-season, which was his third.

"He then built up some consistency and got some AFL games, which we all saw and witnessed. He went out of the team and since then, there hasn't been a lot of continuity. He got quite ill with the flu and missed a lot of training in that period.

"Only in the last three weeks or so has he got good continuity back. Andrew Phillips going out, that circumstance helps, and some continuity at training helps. He'll get an opportunity based on that.

"There's the whole picture over a three-year period. It's clear and laid out."

McKay's return will come as Carlton makes a host of changes for Friday night's clash with St Kilda, with defender Jacob Weitering likely to miss with a calf injury.

He will join Wright and Phillips in going out of the side, but veteran Kade Simpson will return having been a late omission from last week's clash with Brisbane due to a tight calf.

Caleb Marchbank, who spent Saturday night in hospital having reported a raised heartbeat, has been given the all-clear from the cardiologist and is expected to play.

But it's McKay's inclusion that will have Carlton fans excited, with Bolton saying that he's desperate for the young forward to take his opportunity and impress.

"I think we all have seen (McKay's glimpses)," Bolton said.

"Me, more than anyone at this football club, started with Harry in that draft. That crew that started with me, I'm really keen to see do well and I really hope he does.

"No one, including me, wants Harry to not be a great AFL player, or we're deliberately holding him back. We've just had to make informed decisions based on what I've just outlined."

Bolton said he sees similarities with Brisbane forward Eric Hipwood in McKay's game.

The comparisons came after Hipwood dined out on Carlton last week, kicking a career-high six goals in Brisbane's convincing 65-point win.

McKay has kicked multiple goals in four of six games so far this year, including a career-best four against West Coast in Round 5, with Bolton hoping to see similar on Friday night.

"He's a really mobile tall, a little bit like Eric Hipwood," Bolton said.

"He's got some similarities in that he can twist and turn and he's mobile. He uses the ball well, so we want him to use that agility and mobility.

"But when it's his turn in the contest, we want him to launch at it and play with a free spirit."