O'Shea (25), an accountancy student at the University of Otago, begins an intense six-week period of racing at Timaru this Saturday.
The highlight will be the Melbourne Track Classic against the Olympic champion on March 22.
Sanchez (36) won the Olympic gold medal at Athens in 2004 and London in 2012. He also won world titles in 2001 and 2003.
''I'm very excited to be racing against him,'' O'Shea said.
''You don't know how you will respond until you are in that situation.
''I race well under pressure with runners beside me. With some fast races I will be able to reduce my time.''
O'Shea's fitness has been helped by the $120 foam roller he bought from the United Kingdom two weeks ago.
''We have them in the academy gym but I wanted to be able to use it whenever I needed,'' he said.
''It means I can massage out any tight muscles on the spot when it is needed. I've got my money's worth already.''
O'Shea has noticed the difference because he has been plagued with niggling injuries over the last three years.
He had a serious groin injury that kept him sidelined for most of 2011 and he was not able to hurdle in 2012.
''I was tight around the rest of my midriff and by loosening that up it took the pressure off my groin,'' he said.
O'Shea made a significant breakthrough last season when he broke a long-standing Otago record in his specialist 400m hurdles with a time of 50.16sec.
It beat the old record of 50.48sec that Roger Johnson (Ariki) ran at the 1972 Olympic Games semifinal in Munich.
''I took a lot of confidence from that time,'' O'Shea said.
''I had bronchitis at the time and it lets me know there is a lot more to come.''
The qualifying time for the Commonwealth Games in Glasgow is 49.70sec and O'Shea is confident he can reach the standard.
He is one of three athletes hovering close to that time. The others are Waikato-Bay of Plenty athletes Cameron French and Michael Cochrane.
Cochrane set a New Zealand national 400m hurdles record of 49.72sec at the Perth Classic on Saturday. The old record was held by Nic O'Brien in a time of 49.90sec at the NCAA championships in Connecticut in 2003. Cochrane (22), from Tauranga, had a previous best of 50.07sec at the Sydney Classic a year ago.
''I beat both of them at the New Zealand and Australian championships last season.
''The way I have structured my season this year is not to run fast until I reach my peak and then run really fast.''
In previous seasons he has not had top competition when he has raced in New Zealand but that should change this year.
''I've done the times when I've raced against top competition. That is why I'm throwing myself into more international-class races this year.''
O'Shea finished third in the 300m flat race at the track classic on the Christ's College grass track in Christchurch on Saturday in 34.58sec. It was won by Alex Jordan (Wellington) in 34.41sec. Tama Toki (Auckland) was second in 34.45sec.
O'Shea will race at the Canterbury championships, Timaru (March 1), Auckland Grand Prix (March 8), Sydney Track Classic (March 15), Melbourne Track Classic (March 22), New Zealand championships, Wellington (March 28-30), Australian championships, Melbourne (April 4-6).
Daniel O'Shea: At a glance
Age: 25.
Occupation: Otago University accountancy student.
Sport: Athletics.
Coach: Brent Ward.
Events: 400m, 400m hurdles.
Record: NZ senior champion 400m hurdles 2010, 2013; bronze medal Australian championships 2013.
Best times: 100m (10.75sec), 200m (21.57sec), 400m (47.35sec), 400m hurdles (50.16sec).
