Manchester United boss Erik ten Hag admits Friday's training was tough for his players.
United were recovering after their defeat at Chelsea.
United host Liverpool on Sunday and Ten Hag said: "You don't want to come out of bed today but you have to, you have to get out and focus on the next game.
"We have to learn again the lesson, the negative lesson. But also we can take positives from it. We put ourselves in a winning position but we have to take the win over the line.
"At this moment, we are not able to so we have to step up in that matter. But the most difficult part of football, we can do. We put ourselves in winning positions by playing very good football, so now we have to make the next step."