Johnson needs to continue playing physical defense
This is definitely Johnson's number one goal for his upcoming games in the Olympics. Many players on the U.S. roster that are inexperienced in international play are quickly realizing that FIBA rules are quite different from those of the NBA. Specifically, the officials are not afraid to turn a blind eye to contact.
If there's any member of the Men's National Team that can take advantage of being allowed some extra aggression, it's Johnson. While he's generally a bit more known for playing through contact on offense rather than initiating the contact himself on defense, we all know he certainly isn't afraid to do either one.
International basketball is widely known for its disciplined and aggressive defense, and the U.S. roster is going to have to adapt quickly. European teams in particular are very used to playing against tight team defenses, and any lapses on that end will be very damaging. Even in their exhibition game against Spain, a 41-year-old Pau Gasol was able to score 8 points and 5 rebounds.
Keldon should be particularly useful in defending post-ups, grabbing rebounds, and even getting the occasional block down low. At the end of the day though, Johnson will just need to do what he already does well: bring energy. If he can bring the motor fans are used to seeing him with on the Spurs, the U.S. Men's National Team will be in great shape moving forward.