England pace bowler James Anderson says the International Cricket Council has a responsibility to prevent the Test game from being overtaken by one-dayers.
Last week the ICC cancelled the 2013 World Test Championship in favour of the 50-over Champions Trophy.
"We play a lot of one-day cricket - last year we played the Ashes, seven one-dayers in Australia and then the World Cup," Anderson told BBC Sport.
"The ICC [has] a big responsibility to the game of Test cricket."
Anderson's comments come on the day that Australia secured a thrilling two-wicket win over South Africa in front of a sparse crowd in Johannesburg to level the two-match series 1-1.
Writing on Twitter, former England captain Michael Vaughan said: "Why oh why only a two-Test match series?"
The truncated nature of the contest between the Proteas and the Baggy Greens is similar to South Africa's tour of England in 2012, when only three Tests will be played.
"There are obviously concerns because you watch Test cricket around the world and attendances are dwindling," said Anderson.
"We are lucky in England in that crowds are generally sold out and we get good atmospheres at those games, but it is disappointing to see that is slightly different around the world.
"But from a player's point of view, I was talking to [India batsmen] Virender Sehwag and Suresh Raina and I heard them say that their passion is still Test cricket.
"Hopefully that passion the players have will keep the game going for a number of years."
England are not in action until the end of January, when they travel to Dubai and Abu Dhabi for three Tests, four one-day internationals and three Twenty20 games against Pakistan.
The series will be the first time the two sides have met since Pakistan players Salman Butt, Mohammad Amir and Mohammad Asif were given prison sentences of between six and 30 months for their part in a plot to bowl deliberate no-balls in a Test at Lord's in 2010.
Anderson said: "It was good to see such strong sentences because there's no place for [spot-fixing] in cricket.
"If someone is going to carry on doing it now they would be very foolish."
The trial of Butt, Amir and Asif saw several other Pakistan players also named in connection with fixing during the case at Southwark Crown Court.
Anderson admitted the events of last summer could prompt a spicy atmosphere between the teams.
"A lot has gone on in the last 12 months with these two teams so it is going to be an interesting one," he said.
"There is no love lost but nowadays cricket isn't the game it used to be in terms of sitting down at the end of the day and having a beer with the opposition.
"There are not many teams we form good relationships with because such is the contest on the field and the amount of cricket we play. I wouldn't single out Pakistan as being any different to any other international team."