To cover that hypothetical scenario, here is a scouting report on Trapp.
Along with Bayer Leverkusen goalkeeper Bernd Leno, Trapp is one of the Bundesliga's premier penalty savers.
Covering the right side, Trapp exhibited outstanding lateral speed to his left, as he made a one-handed save to deny Schalke centre-forward Klaas-Jan Huntelaar.
Hoffenheim central attacking midfielder Roberto Firmino also had his spot-kick saved by Trapp.
Being agile, rangy and reading the game well is why Trapp has consistently thwarted opposing players in clear-cut scoring situations.
Rushing out, Trapp smothered the shot of Mainz centre-forward Shinji Okazaki.
With the ball bouncing fortuitously to Bayern Munich centre-back Dante, his snap-shot was foiled by a reflex save from Trapp.
Despite Augsburg central attacking midfielder Halil Altintop creating his own shot while tightly marked, Trapp managed to deflect the shot away from goal.
Trapp was not world class last season, according to the German footballing media.
You should not get carried away by Trapp's highlight-reel saves.
He was out of position when Hertha Berlin central attacking midfielder Alexander Baumjohann delivered a cross for Hertha right attacking midfielder Sami Allagui.
Borussia Dortmund right attacking midfielder Pierre-Emerick Aubameyang cashed in after Trapp failed to punch the ball away from goal.
Trapp failed to close his legs when Hannover 96 centre-forward Didier Ya Konan scored.
Stuttgart left attacking midfielder Timo Werner capitalised after Trapp flapped at the ball.
Freiburg substitute Nicolas Hofler scored after Trapp did not adequately cover his near-post.
|League Only||Kevin Trapp||Pepe Reina|
|Saves Per Goal Conceded||2.4||3.7|
|Saves Per Game||3.9||3.6|
Trapp is statistically comparable to Reina, even though there is a significant gap in experience.
"I have been really happy at Napoli and I feel loved," Reina said, per La Gazzetta dello Sport (h/t Phil Kirkbride at the Liverpool Echo). "I have never ruled out the possibility to remain at Napoli."
If Reina leaves in the summer transfer window, Liverpool should consider signing Trapp.
Statistics via WhoScored.com