Sarah Healy and Kate O'Connor were two parts of a medal trio in the European Indoors two weeks again in the Netherlands, and they are ready to impress again - this time on the global stage in Nanjing.Unfortunately the other medallist from those championships, Mark English, has had to withdraw from the World Indoors Men’s 800m through illness, while Cian McPhillips (injury) also misses out at the same distance.Over 550 athletes from 127 countries are entered in the global event, with 11 defending champions and 20 medallists from the Paris Olympics geared up for action.Healy is riding the crest of a wave after her recent gold medal winning performance over 3000m at the European Indoors in Apeldoorn. The 24-year-old has a season’s best of 8:30.79, which ranks her fourth in the field this year going into Saturday’s straight final at 11:15am Irish time. Her main rivals are Freweyni Hailu (Ethiopia), who won gold over 1500m at these championships last year, and her compatriot Birke Haylom. The US' Whittni Morgan also hopes to challenge for the podium places, as will Olympic 1500m silver medallist Jessica Hull of Australia. Kate O’Connor starts the Irish bid on Friday morning in the pentathlon, less than a fortnight after her brilliant bronze medal at the European Indoors where she set a new national record of 4,781 points, achieving personal bests in four of her five events.The 24-year-old is ranked second on season’s bests going into these championships behind only European Indoor gold medallist Saga Vanninen (Finland). Hungary’s Xénia Krizsán, who was seventh in the heptathlon in Paris, and the USA’s Taliyah Brooks have both yet to compete this year but should be in the medal mix, but if O'Connor comes close to her national record she will be in the picture. Sophie O’Sullivan and Andrew Coscoran are also in action on the opening day in the heats of the women’s and men’s 1500m respectively. O’Sullivan, who just missed out on a semi-final spot in the event at the Olympic Games in Paris last summer, has been training in Australia recently and clocked 4:06.74 outdoors to open her season at the Perth Track Classic earlier this month.Coscoran has lowered the Irish 1500m record this year, as well as the one mile and 3000m records. He was sixth in the 3000m final in the Euro Indoors. His 3:33.40 season’s best and national record ranks him fourth of the entrants this year in the 1500m, while his 7:30.75 3000m season’s best and national record places him fifth of the entrants in that event. The 1500m is two rounds (heat on Friday and final on Sunday) with the 3000m being a straight final on Saturday at 11:33am Irish Time.Joining Coscoran in the 3000m final will be James Gormley, who ran well in the heats of the Euro Indoors, just missing out on a final place on his senior international debut. Sarah Lavin will be the last of the Irish team to get her challenge underway when she races in the heats of the Women’s 60m Hurdles on Sunday morning. Lavin finished fifth in the final in the World Indoors in Glasgow last year and will be hoping to improve her season’s best of 7.92 seconds in finishing fourth in the European Indoors. Both the semi-final and final of Lavin’s event take place in the Sunday evening session to conclude the championships. Get the latest sports headlines straight to your inbox by signing up for free email alerts.