The defender has proved a more than able deputy for Rio Ferdinand this term, but it's his displays in the win over Manchester City and the draw in Marseille that have shown beyond doubt he can handle the big occasion.
Smalling admits that he didn't expect to play quite so many important matches following a summer switch from Fulham, but he's developed a taste for it and now doesn't want to surrender his place.
"When you get the shirt and a position in the team you don't want to give it up," he said. "I understand that Rio is the main man and his are big shoes to fill. I just have to make sure whenever another opportunity arises I keep taking them.
"I know I will have to bide my time, but hopefully with these performances and the sort of games and massive occasions I have been playing in I can justify the manager's faith in me. Hopefully I get many more games because as each match passes I'm getting more confident and that will only help me improve."
The Reds are challenging in three competitions and Smalling says the players are well aware of the challenges but is confident United can produce the goods.
"It is a massive stage of the season for us," he says. "We've been at the top for a while now in the league and it's time to kick on and put a bit of space between us and the rest. As players you relish these big games. There's a real togetherness in the squad and hopefully we can kick on in every competition."