Jack Sock: Nick Kyrgios is getting better every week

The Unites States will face Australia in the Davis Cup quarterfinals this weekend in Brisbane. The top players on each team, No. 15 Jack Sock and No. 16 Nick Kyrgios, are good friends off the court and almost in the same position in the rankings.

Both have also been climbing the rankings. Kyrgios almost upset Roger Federer in the semis in Miami last week and was a quarterfinalist in Indian Wells. Sock reached the semis in Indian Wells, where he lost to Federer, and reached the quarters in Miami, losing to Rafael Nadal.

As the highest-ranked American, Sock will face Australia's Jordan Thompson on Friday, and is scheduled to play Kyrgios in what could be an important fourth rubber.

The 24-year-old said that Kyrgios is getting better each week.

“The skill and talent has always been there, everyone knows that,” Sock said. “Mentally, he's doing a lot better job on court. It seems like he's letting things go a little better. If he's on that day and into it, he's tough.”

On Saturday, in the doubles, it is scheduled to be Americans Sam Querrey and Steve Johnson against Sam Groth and John Peers.