Ole Gunnar Solskjaer admits Aaron Wan-Bissaka and Daniel James have added some pace to the Manchester United squad.
Wan-Bissaka was a £50m signing from Crystal Palace this summer while James arrived in a £15m deal from Swansea.
Both youngsters are in line to make their first appearances against Perth Glory on Saturday.
Solskjaer has put his squad through their paces in Australia with improving fitness levels a top priority for the United boss.
And he has been discussing the speed of Wales winger James, although he believes his new teammate could run him close.
Asked if there was anyone quicker than James, Solskjaer said: "Maybe Aaron Wan-Bissaka!"
"The two of them do have top, top speed. Modern football is stop start, it is go again, speed, tempo, quality, so those two have put their maker down.
"Of course, with our boys, we have got some quick ones."
On his two new signings, the United boss added: "I think they (the new signings) have been great.
"Dan came in on the first day, Aaron has just come to tour now and has been training here. I think they enjoy it.
"Of course it is a step up for them with the quality of team-mates and quality of training."
United take on Perth Glory on Saturday before facing rivals Leeds in Australia next week.
Romelu Lukaku and Paul Pogba, who have both been linked with moves away this summer, are expected to play some part.
