The 39-year-old, whose record is made up of 932 appearances for his club, 64 for Wales and four for Britain's Olympic team, made his senior debut as a 17-year-old substitute in United's 2-0 defeat by Everton on March 2, 1991.
He is the seventh British player to make 1,000 first-class appearances but is some way short of the record 1,387 established by former England goalkeeper Peter Shilton between 1966-97.
Giggs has defied his age to carry on putting in top-class performances in some of the biggest games, with his last goal coming as recently as last month in a 2-0 Premier League victory at Queens Park Rangers.
On Friday, he signed a contract to carry on playing for another season, taking him past his 40th birthday as his recipe of yoga, hard work and healthy eating continues to work wonders.
United had not won a league title for nearly a quarter of a century when the slim and graceful Welsh teenager started his nifty runs up the left wing but now he is the most decorated player in English football with 12 Premier League winner's medals, four FA Cup winner's medals and two Champions League winner's medals among his collection.
Tuesday's match is his 134th Champions League appearance and he has scored 28 goals. He holds the record of being the oldest player to score in the competition after netting in a 1-1 draw at Benfica in September 2011.
United and Real started the match level at 1-1 in the tie following last month's first leg in Madrid.
