FAST-RISING junior tennis star John Hui is in line for his maiden Davis Cup call-up. The 15-year-old is on the shortlist of five players battling for four places in the team to meet Indonesia in the first round of the Asia-Oceania Zone Group One tie to be held in the territory from March 25 to 27. Hong Kong International School pupil Hui has improved leaps and bounds since his father hired Australian player Mark Jeffrey as his training partner early this year. Jeffrey, 26, was in the world's top 250 eight years ago before his fledgling tennis career was ended by a back injury after only one year on the professional circuit. He has spent the last nine months helping to nurture Hui's talents and travelled extensively with the youngster on tennis tours. Others vying with Hui for the honour of representing Hong Kong in the Davis Cup are Michael Walker, Colin Grant and Pang Lui and also Malvin Tong.