Julen Lopetegui is on Nottingham Forest’s radar as the club explore possible successors to struggling manager Steve Cooper. Lopetegui is out of work after leaving Wolves on the eve of the season. Forest are also thought to retain an interest in the former Eintracht Frankfurt manager Oliver Glasner. Cooper is expected to take charge of Forest’s match at Wolves on Saturday, but his position is extremely precarious after Wednesday’s humiliating 5-0 loss at Fulham, a fourth straight defeat. Cooper said he was “embarrassed” to receive the almost universal backing of the away supporters who sang the Welshman’s name at full-time. Evangelos Marinakis, the Forest owner, holds grave concerns about the direction of travel under Cooper. Forest are six points above the relegation zone after one win in 11 games since September. Marinakis also owns Olympiakos and this week sacked Diego Martínez with the club fourth in the Greek top division but in recent weeks he has been encouraged to give Cooper time. It is not the first time Cooper has been under significant pressure but there is a frustration at Forest that they are underachieving after investing more than £100m in the squad in the summer. They sanctioned the £47m sale of Brennan Johnson to Tottenham to ensure they hit financial fair play targets. Forest handed Cooper a new contract in October last year after five straight defeats but he is under renewed scrutiny after losses to West Ham, Brighton, Everton and Fulham. Forest hoped Cooper would turn things around, starting against Fulham. Cooper held his pre-match press conference on Thursday as scheduled. Asked whether he believed the Wolves game could be pivotal to his future, Cooper replied: “It is not a thought process I believe in using. Of course, we are disappointed with the results, particularly the one last night and the performance, but more than ever you have to show belief and character in what you want to be and who are you are and what you stand for and what the club and the supporters need to see.” Marinakis was in attendance at Craven Cottage but is understood to have left with about 20 minutes to play, after Fulham scored their fourth goal. After the game an accreditation lanyard purportedly belonging to Marinakis was allegedly found in a nearby bush. Cooper did not speak to Marinakis after the game but did so with Miltiadis, Marinakis’s son, and the Forest sporting director, Ross Wilson. Cooper, asked whether he felt let down by his players, replied: “Situations like this provide opportunities and the one we have in the short term is to show supporters what it means to play for this club on Saturday. We want to see people stand up and be counted. I know I will.”