The Greek custodian, who is celebrating his 38th birthday on Tuesday, has been left out in the cold in the Premier League despite playing an influential role in helping the Teessiders end their seven-year exile with 22 clean sheets and only 31 goals conceded in 46 Championship games.
The main reason for his absence is down to former Barcelona and Spain international, Valdes, who was brought in by boss Aitor Karanka on a free transfer in the summer.
Valdes endured a shaky start to his time at the Riverside Stadium, but the 34-year-old has steadily gone on to show why he has been regarded as one of the world's best shot-stoppers in recent games.
And, while Konstantopoulos has suffered because of Valdes' signing, he has nothing but praise for his team-mate.
"He is a good lad, he works hard every day and we push each other," he said in the Gazette.
"We know all about his pedigree and his achievements from his career, that counts a lot as a personality at a football club.
"He has been a joy to work with and we have always been a very close group, since I have been here really, the new lads like Victor have gelled."