Today's #NBO21 semifinals:⁠⁠ ⁠⁠ 🇺🇸 Reilly Opelka 🆚 Tsitsipas NB 3 p.m.⁠⁠ 🇺🇸 John Isner 🆚 Medvedev NB 8 p.m.⁠⁠ ⁠⁠ Could we see an all American final in 🇨🇦?⁠⁠ ⁠⁠ #AtlantaOpen | #USOpenSeries