"They did very well in the game we played against Iceland," said Southgate at his pre-match press conference.
"Obviously that deeper position, Mason doesn't play for his club but I think it's possible for him. He's a very intelligent player, he can play four, eight or 10. I think he would be able to adjust as required.
"There's no doubt the balance of those two [Mount and Rice] is good. But equally James Ward-Prowse was good [against San Marino] the other day and Kalvin Phillips is in excellent form as well.
"It's an area on the pitch where we are starting to get some options. It's been great to have Jude [Bellingham] with us as well. Like almost every position on the pitch we have a lot of competition for places."
With Liverpool's Jordan Henderson out with injury, Mason Mount has stepped into the midfield role excellently.
If he can also produce the same level of leadership as Henderson, he might displace the Liverpool captain from the team permanently.
