Complex sentence: After playing only sparingly during the seasons first two months, by June 2000 he finally established himself as an MLB regular, though he played primarily at designated hitter with Kelly sticking with veteran Ron Coomer at first base.
Split into simpler sentences: After playing only sparingly during the seasons first two months, by June 2000 he finally established himself as an MLB regular. However, Ortiz played primarily at designated hitter as manager Kelly stuck with the veteran Ron Coomer at first base.