That's Dr. Ivo...great dude. Guy he's playing is Dudi Sela, they have actually played doubles together before, funny to watch.
Sela is the shortest guy in Top 100, Dr. Ivo (Ivo Karlovic) is the tallest in Top 100.
Sidenote......I was playing a tournament in Germany, I was in locker room. Karlovic was in the shower and forgot to bring a towel. I walked by shower and he asked me to run to the front and grab him a towel. He is the biggest naked dude I have ever seen in my life. Just thought I'd share.
Note: I brought him three towels, as I said, big naked dude.
Karlovic and Sela are nice guys, cool dudes to hang out with.