A fast and skilful onballer, Christensen was best afield for the Cats' VFL team in its match against Werribee on the weekend.
The 20-year-old has already played six AFL games this season after making his debut against Fremantle in round two.
He had to give up his spot after suffering concussion in Geelong's narrow win over Carlton in round nine.
While Selwood's predicament has opened the door for Christensen to earn a recall for Saturday night's clash with St Kilda at the MCG, Cats coach Chris Scott said his good form in the VFL meant he probably would have been selected anyway.
"He's shown at AFL level that he can handle the situations we require of him," Scott said at Skilled Stadium on Tuesday morning.
"We would expect that he would come in and play well this week and hold his spot for some time."
Other Geelong players in the mix for selection against the Saints include veteran David Wojcinski, who was rested last weekend, and emerging midfielders Steven Motlop, Josh Cowan and Cameron Guthrie.
"It's not a bad situation to be in," Scott said. "We've got some young players that are playing well."
The last meeting between the Cats and the Saints, which took place in round one on a Friday night at the MCG, was a turgid affair.
On that occasion, both teams had men behind the ball and Geelong had only one goal on the board with five minutes remaining in the third quarter.
An attacking burst just before the final change dragged the Cats back into the contest, and they snatched a three-point win when Darren Milburn snared the winning goal with only 19 seconds left on the clock.
While the margin was close, fans of both teams will be hoping for a more free-flowing contest this time around.
However, Scott said, "It's really hard for me to comment on the spectacle.
"It's not down the bottom of my list of priorities, but it's towards the bottom.
"The most important thing is that we play well and we win. We're prepared to do anything within the rules to get that done.
"But I said after that round-one game that we would like to attack more. We think we're a more attacking side than we showed that night, and in some games we've done that quite well.
"But the most important thing against St Kilda is that we defend as well as they do, and we know they're going to defend well."
