Complex sentence: Gilchrist's regular selection for Australia meant that he was rarely available for domestic selection after he became the Test wicket-keeper in late-1999; and between 1999 and 2005, he made only seven first-class appearances for his state.
Split into simpler sentences: Gilchrist's regular selection for Australia has meant that he is rarely available for domestic selection. He became the Test wicket-keeper in late-1999, and between 1999 and 2005, he made only seven first-class appearances for his state.