Question: Which tennis player played in the Masters, Daniel Vacek or Yan Zi?

Context paragraphs:
Wei Yan Tao: Wei Yan Tao (simplified Chinese: 魏炎涛; born 12 February 1986) is a male table tennis player from China.  He joined the Chinese National Table Tennis Team in 2003.  Wei is left-handed, shakehand grip.  He played for Zheshang Bank Table Tennis Club in China Table Tennis Super League in 2008 and 2009.  He is the coach of Guangzhou Tianhe Taibaijinxing Table Tennis Association from 2009 till 2016.

1993 Volvo International – Singles: The 1993 Volvo International was a tennis tournament played on outdoor hard courts at the Cullman-Heyman Tennis Center in New Haven, Connecticut, United States and was part of the Championship Series of the 1993 ATP Tour.  The tournament ran from August 16 through August 23, 1993.  Stefan Edberg was the defending champion but lost in the second round to Daniel Vacek.  Andriy Medvedev won in the final 7–5, 6–4 against Petr Korda.

1993 Volvo International – Doubles: The 1993 Volvo International was a tennis tournament played on outdoor hard courts at the Cullman-Heyman Tennis Center in New Haven, Connecticut, United States and was part of the Championship Series of the 1993 ATP Tour.  The tournament ran from August 16 through August 23, 1993.  Kelly Jones and Rick Leach were the defending champions but only Jones competed that year with Paul Annacone.  Annacone and Jones lost in the semifinals to Cyril Suk and Daniel Vacek.  Suk and Vacek won in the final 7–5, 6–4 against Steve DeVries and David Macpherson.

Yuan Meng: Yuan Meng (born 9 May 1986) () is a former Chinese female professional tennis player.  She is China's fifth-highest ranked women's singles player after Zheng Jie, Li Na, Peng Shuai, and Yan Zi.  Yuan has won four ITF singles titles and one ITF doubles title.

Jan Vacek: Jan Vacek (yahn VAH-tseck; born May 10, 1976 in Prague) is a retired professional male tennis player from the Czech Republic.

Yan Zi (tennis): Yan Zi (; ; born November 12, 1984), is a retired Chinese-born Hong Kong female professional tennis player.

Tennis at the 2010 Asian Games – Women's doubles: At the 2010 Asian Games in the Women's doubles tennis event, Zheng Jie and Yan Zi were the defending champions, but only Yan chose to participate, she partnered up with Peng Shuai.

2006 Qatar Telecom German Open – Doubles: The Doubles Tournament at the 2006 Qatar Telecom German Open took place between May 5 and May 13 on the outdoor clay courts of the Rot-Weiss Tennis Club in Berlin, Germany.  Yan Zi and Zheng Jie won the title, defeating Elena Dementieva and Flavia Pennetta in the final.

Mervana Jugić-Salkić: Mervana Jugić-Salkić (born 14 May 1980) is a Bosnian former tennis player.  She turned professional in 1999, and reached her highest singles ranking on 21 June 2004, when she was ranked World No. 99.  On 10 July 2006, Jugić-Salkić reached No. 59 in doubles, after winning ASB Classic in 2004 with Jelena Kostanić and Internazionali di Modena in 2005 with Yuliya Beygelzimer.  She also won 15 singles and 43 doubles events organized by International Tennis Federation.  Jugić-Salkić represented Bosnia and Herzegovina at the 2004 Summer Olympics, but fell to Maria Elena Camerin in the first round.  During her long career, she defeated players such as Yan Zi, Victoria Azarenka, Bethanie Mattek, Sania Mirza, Anabel Medina Garrigues, Nuria Llagostera Vives and Sybille Bammer.

Daniel Vacek: Daniel Vacek (born 1 April 1971) is a former tennis player from Czechoslovakia and the Czech Republic who turned professional in 1990.  He reached the quarterfinals of the 1995 Paris Masters, the 1998 Canada Masters and the 1998 Cincinnati Masters, and achieved a career-high singles ranking of World No. 26 in January 1996.

Supporting paragraphs: Daniel Vacek Yan Zi (tennis)
Answer: Daniel Vacek