Adam Lallana thought Southampton manager Nigel Adkins was joking when he told the midfielder about his England call-up.
The 24-year-old was one of three players added to Roy Hodgson's England squad following a number of withdrawals ahead of the World Cup qualifier against Ukraine at Wembley on Tuesday.
Chelsea duo John Terry and Ashley Cole were ruled out over the weekend, and Theo Walcott has returned to Arsenal after contracting a virus.
Daniel Sturridge was also unable to train on Monday due to illness, leaving Hodgson will little choice but to draft in replacements.
Lallana has enjoyed an impressive start to his Premier League career at Southampton this season but he was still shocked when the call came from Adkins on Monday morning.
"I didn't think the gaffer was being serious when he called to tell me this morning," Lallana told Southampton's official website.
"I was at home about to head into the training ground when he called - I must have asked if he was having me on a dozen times!
"I'm totally shocked to be honest."
Lallana was named as Southampton skipper this summer and has represented England at Under-18, Under-19 and Under-21 levels.
The versatile midfielder is well aware that he is unlikely to make his senior debut but is thrilled just to get the chance to link up with the senior squad.
"It's such a proud accomplishment to be called up to play for your country at any level, but to be called into the senior side is probably the proudest moment of my career so far," added.
"It is every player's dream to represent your country at the top level.
"I'm realistic in accepting I might not be that heavily involved, but the fact that I will be around such experienced international players is something I am really excited about."
Lallana will link up with former Saints team-mate Alex Oxlade-Chamberlain and with Walcott also having been a part of the youth set-up there it speaks volumes for the south coast side.
"It reflects really well on the club," Lallana said.
"It shows just how far Southampton has come to have an English player represented at national level.
"We have a lot of talented young English players here and I'm sure that I won't be the last person to represent our country."