Shoulder stated his belief that the elegant young midfielder is ready, if needed, for promotion to Mark Hughes' senior squad.
Simon is viewed as the senior player of the under-21 pool and will win his tenth cap at that level on Friday evening.
Shoulder said of the Haverfordwest-born 21 year: "Simon is by far the most advanced of our under-21s and if you are looking for someone to step up a grade he's the best we've got.
"He's the obvious choice. He's very positive and level headed and I feel he could handle it now."
For his part, Simon said that events at the Lane have come into his thoughts while away on international duty.
"It's in the back of my mind what's going on at Spurs and what's going to happen when a new manager comes in.
"Everyone is on a level and starting again to impress a new manager, hopefully I can do that.
"It's good to get away with Wales because things are a bit hectic at the moment and hopefully it will have settled down when I get home."
Wales under-21 coach Jimmy Shoulder has handed Simon Davies a massive boost ahead of the European under-21 championship qualifier against Armenia in Abovyan.