Jimmy Gopperth says it is "scary" to see how far Wasps' England hopeful Jack Willis will go in top-level rugby.
Uncapped flanker Willis produced a command performance in front of England head coach Eddie Jones as Wasps reached their first Premiership final for three years with a 47-24 drubbing of Bristol.
The 23-year-old scored a try, saved another with a brilliant tackle to deny Bristol fly-half Callum Sheedy and bossed the breakdown area like a seasoned veteran.
On current form, it would be a monumental surprise if he does not feature during England's six-game autumn schedule, which has matches against the Barbarians, Six Nations opponents Italy and four Autumn Nations Cup fixtures.
Willis was selected by Jones for England's 2018 South Africa tour, but a serious knee injury put paid to his chances and sidelined him from the sport for several months.
"Jack is going from strength to strength," said Wasps centre Gopperth, whose 22-point haul underpinned Bristol's demise.
"He is still so young. It's scary to see how far he is going to go.
"The way he has battled back (from injury), his self-determination and the way he has stayed on point.
"It would have been very easy for a young guy to mentally switch off and go 'Jeez, I got the call-up, this has happened to me, stuff this, stuff that' and blame everyone else.
"But he has actually gone the other way and gone 'I am going to work harder'. If he is not Premiership player of the year, something has gone wrong."
Willis has proved instrumental in Wasps' spectacular climb from the Premiership's lower reaches they occupied earlier this year.
Under head coach Lee Blackett, they have risen rapidly, winning 12 of their last 13 games to book a Twickenham appointment with Exeter on October 24 in a repeat of the 2017 final that Chiefs won after extra-time.
Gopperth added: "Straight away, then (in 2017), it was 'Wasps have got to the final!' We didn't really expect it.
"We were playing awesome rugby and we had some star-studded guys, but we probably played our final the week before. That last-ditch play-off win against Leicester was huge for us.
"We went down there (Twickenham) to sort of ride the wave, whereas I think we've now got enough experience in finals that it's different now.
"We understand what is in front of us. A lot of hurt from that can go a long way for a bit of motivation.
"We've given ourselves an opportunity to be on the big stage. Before Christmas, people wouldn't have backed that. The way we have fought together and trusted our process has been brilliant."
Wasps are chasing a first Premiership title since 2008, when players like Lawrence Dallaglio, Josh Lewsey, Phil Vickery and James Haskell ruled the roost.
Unlike on that occasion, though, when the final was watched by a then world record crowd for a club game of 81,600, it will all unfold behind closed doors.
"Going down to Twickenham, it will be quite eerie," Gopperth said.
"When you are playing with no fans, at the end of the day rugby is rugby and you can stay in the moment within your group, and when you are playing your focus is solely on the game.
"But when you score tries and make turnovers, that's when the crowd erupts and you get that emotional drive.
"It's weird, if you go on to win the thing, to be by yourselves. You would love the supporters to be there."
