Chris Smalling accepts he will have to make way in the Manchester United defence once Rio Ferdinand returns to full fitness.
Smalling made his fifth UEFA Champions League start on Wednesday night and produced another accomplished display as United earned a 0-0 draw at Marseille.
The 21-year-old centre-half has been handed a chance to impress due to the calf injury Ferdinand suffered in the warm-up for the Wolves defeat earlier this month.
And although the summer signing from Fulham is aware he cannot expect to keep out the England captain, he has shown he is an able understudy.
"When you get the shirt and a position in the team you don't want to give it up," said Smalling.
"I understand that Rio is the main man. But when he got injured it was time for me to step up.
"They are big shoes to fill. Hopefully through my performances and the sort of games and massive occasions I have been playing in, I repay the manager's faith and justify him playing me.
"I know I will have to bide my time but I am always going to be ready because no player wants to be sitting on the bench."
After coming off the bench against Wolves, Smalling was handed his fourth Premier League start in the derby against title rivals City and impressed as United claimed a crucial 2-1 win.
The Red Devils have more big games coming up as even before Marseille visit Old Trafford for the second leg on March 15, United must face Chelsea and Liverpool in matches that will be crucial in the Premier League title race.
"I didn't expect to get games of this nature yet," Smalling added.
"It's not the amount of games I have played in that has been a surprise because I hoped to be given a few, but the types of them.
"I had the Manchester derby a couple of weeks ago and now Marseille, which was a totally different experience.
"I heard a lot about the stadium. You don't often get 90 per cent of the fans booing you just doing your warm-up before the game.
"We are at a massive stage of the season now, with so many big games coming up.
"But they are matches you should relish. I am really looking forward to the run-in."