The youngster stepped in between the sticks in place of England’s number one Karen Bardsley, who was stretchered off with a shoulder injury after just three minutes.
As the Super League’s top two locked horns and with crucial points at stake, Roebuck was called into action on a number of occasions but produced a stunning display – and a match-saving stop to deny Drew Spence – to preserve a draw for the league leaders.
Christiansen was impressed with her side’s defensive performance; in particular, newly-contracted 18-year-old Roebuck’s role.
“If it wasn’t for Ellie, I think we’d be walking away with no points,” the midfielder stated.
“She was absolutely fantastic. She came off the bench early on in the game and played like an absolute pro.
“She is fully deserving of her professional contract at the Club. She’s proven why she’s earned it.”
Bardsley was not the only casualty at Kingsmeadow, as captain Steph Houghton was also forced off with injury.
READ: League leaders earn hard-fought point
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Christiansen added she feels City’s strength in depth will prove invaluable, as the Blues chase four trophies towards the end of the 2017/18 campaign.
“We’re a team of leaders,” she continued. “It’s not about losing people. It’s about stepping in and doing a job for the team.
“That’s why we’ve got a big squad and players who are up to the level to be able to play for us and perform.
What a performance by @EllieRoebuck_ 🤲 #mancity pic.twitter.com/PtscypK51h
— Man City Women (@ManCityWomen) February 1, 2018
“That’s probably why we got the point (at Chelsea). They threw the kitchen sink at us but we proved we haven’t just got the possession side of the game – we’ve got a lot of grit as well.
“The essence of the game wasn’t necessarily as expected in terms of outcome. From a neutral perspective, the teams cancelled each other out.
“We expected Chelsea to come right out and throw everything at us. They did that. We proved that sometimes, when things aren’t going your way offensively, sometimes you’ve got to put in a defensive performance.
“We have players across the park who can fill in and play. Everyone can do a job. We’ve got exciting young players and we’ve proven we’ve got good strength in depth, such as with Ellie coming off the bench and performing the way she did.
“Come the end of the season, that point might be pivotal. We kept another clean sheet and came away with a point against Chelsea.
“We’re happy with that.”