Manchester United boss Ole Gunnar Solskjaer says they must be active this summer.
Solskjaer has warned United cannot afford to stand still this summer as he looks to build a squad capable of taking on the toughest challenge yet.
"The fear of standing still or going backwards is always there, you would do that if you don't improve. There are many ways we can improve, we can improve on the training ground [and] we can improve with signing players," he said.
"We know the challenge ahead, the first few steps were the easier ones to take, the last step is the most difficult one. The challenge to get the points tally we want for our ambitions is a challenge we want to take head-on.
"To bring the right types of players in is going to be important."
