The 20-year-old, who is on loan at Anfield for the next two seasons from Atletico Madrid, was hauled off after 22 minutes at Upton Park on Saturday evening during his side's 3-1 defeat to West Ham United. No injury has been reported, so it is believed that the decision was a tactical one from manager Brendan Rodgers.
However, despite being substituted so early, Karanka has backed a player that he tried to sign last year to shine in the Premier League.
"I tried to sign him last season, but it was difficult for me. He was playing at Atletico Madrid, and I know him well because I managed him with Spain Under-16s. I tried to convince him to come here, but it was not possible," the Boro boss told the Northern Echo.
"I think he's an ideal player for the Premier League. He's very strong and very good with his feet. He is young and has everything to enjoy success here in England. He will be a very good player in the future."
Karanka's Boro will take on Liverpool in the League Cup this evening.