Kroos is expected to sign for United in a £20 million deal.
Keown told the Daily Mail: "Toni Kroos is a good bit of business for Manchester United, but he is only the first piece of the jigsaw. They still need to bring in reinforcements across the squad if they want to get back to where they were. However, a signing like this does show the power United still have.
"People questioned whether being out of the Champions League next season would affect their ability to buy top names. Well, here's your answer.
"It's good to get any transfers done before a World Cup so that the player's mind is clear, and it's particularly helpful if that player goes on to play a starring role in the tournament."
For the big stories and the banter follow us on Twitter: @tribalfootball