Jan Kirchhoff confesses he should be able to last 90 minutes after two months of Premier League football, but his energy levels continue to “fall into a big hole”.
January signing Kirchhoff has emerged as a key figure for Sam Allardyce’s Sunderland side after shaking off the rust from his nightmare debut in the 4-1 defeat at Spurs.
But the defensive midfielder’s big shortcoming remains his stamina levels; tiring badly in the final 30 minutes which has coincided with Sunderland’s control of proceedings dipping in each of the last three games against Crystal Palace, Southampton and Newcastle.
Kirchhoff endured issues with his fitness both at former club Bayern Munich and during a loan spell at Schalke last season after injuries limited him to just 14 Bundesliga starts in the two-and-a-half years prior to arriving at the Stadium of Light in a £750,000 deal.
The 25-year-old - who played another 90 minutes in a behind-closed-doors friendly against Middlesbrough last week - admits his conditioning remains an issue, despite his work on and off the pitch.
Kirchhoff said: “To be honest, it’s a problem for me in the last 20 minutes.
“There’s days for me where there’s no issue and I can stay with it.
“But there’s ones like the derby where I fall into a big hole and I can’t manage to stay with the intensity of the game.
“I should be able to do that and I expect that from myself.
“I worked really hard in the two weeks before the derby, but I’m not at my top level right now.
“I have to keep on to get it managed.”
Allardyce has lauded the impact of Kirchhoff, who has moved ahead of Sunderland’s longest-serving first-teamer Lee Cattermole in the holding role in front of the back four.
But Kirchhoff accepts that Allardyce will have to keep withdrawing him from the action in the latter stages if he is unable to prove his fitness.
“I’m happy that the manager sees a player in me and I like to stay on the pitch for 90 minutes,” he added.
“But I think the key at Newcastle was we lost the control in midfield after 70 minutes and were not able to win our battles in there.
“You have to make a change. It doesn’t matter who it is.
“It was the right decision to do it and I can understand the decision to take me off, because in the first hour, I was a lot better.”