Holding the No. 1 spot for four straight years has been Jim Gruenwald, a veteran with tremendous experience. Gruenwald has placed in the top 10 at the Worlds and Olympics each time he has competed, with his best performance a fourth place in 2003. Gruenwald severely injured his shoulder in the World semifinals against superstar Armen Nazarian of Bulgaria, and has been in rehabilitation. The U.S. Nationals could mark his first event since the injury.    Without the injury, Gruenwald would remain the strong favorite to win this division. However, nobody knows how well his rebuilt shoulder will withstand the stress of a full national tournament. Should Gruenwald not be ready, he still gets into the Olympic Trials. But having to go through the Challenge Tournament in Indianapolis is something he would love to avoid.    Glenn Nieradka, a past U.S. Nationals champion, has been the top challenger for Gruenwald the last few years. Also a veteran, Nieradka has size and strength at this division, and is always a tough battler. He has an experience edge on most of the opponents, and can still taste the fact that he just missed making the last Olympic Team, losing a fierce battle with Kevin Bracken at the then-138.75 pound division.     Dennis Hall, who has won three World-level medals, holds No. 3 here, but is attempting to drop to 55 kg for the Olympic run. If Hall does not drop down, he still remains a dangerous foe for both Gruenwald and Nieradka. Hall and Gruenwald have a fierce rivalry, with Hall dominating for many years but Gruenwald getting the edge the last four years. For Hall to reach Gruenwald, he may have to beat Nieradka, something that has eluded him recently.    Joe Warren has won a number of events at this weight recently, and has moved ahead of many of the other contenders. Warren has yet to crack into the top three, looking for a breakthrough against the veteran stars who have owned the division. His wins at the Sunkist Kids International and the New York AC Christmas International show his progress and potential. He lost a 3-3 overtime ref's decision to Nieradka in the Schultz Tournament finals, an indication that a break through might be coming soon.    Jacob Hey has proven to be a top challenger, and may also emerge this season. Hey, with the Air Force, has banged heads with Nieradka often in recent seasons. He seems to be much better than many of the rest of the pack, but, like Warren, still has not joined the elite crowd in this division.    After Hey, the experience level and performance of the field drops off a bit. One of the exciting athletes who are on the rise is Willie Madison, who is from the USOEC university resident team. Madison reached the finals at the New York AC Tournament, where he fell to Warren. Another good athlete from that program has been Marco Lara, who captured third at the Sunkist Kids International this year. Nathan Piasecki is also a talent from the USOEC program and a potential high national placewinner.    Those who have already clinched spots in the Olympic Trials through the first three Regionals are Jason Chao, John Habeck and Jason Tolbert. The veteran of this group is Tolbert, who during his prime was a member of Greco-Roman Team USA. Chao has improved his performance training in Colorado Springs, and will be seeking an All-American finish in Las Vegas.    Matt Birner of the U.S. Navy has put himself in the top 10 of the rankings and is somebody to watch closely. Jeremy Wynia has put himself on the map here with fourth place finishes at the Dave Schultz Memorial and the New York AC Tournament. AJ Lavender is a youngster here with potential, as his fourth place at the Sunkist Kids International proved. Marcos Jeantette has experience and will be a tough match for anybody.    The story in Las Vegas will be the performance of top man Jim Gruenwald coming off a serious shoulder injury. Glenn Nieradka is waiting for another shot at Gruenwald, should he be able to compete at a high level. If Dennis Hall stays here, he is always capable of winning a national title, as he won 10 in a row at one point of his great career. Joe Warren wants to be in the finals by beating one of the big name stars. Everybody else will have to have a great tournament if they wish to stay with these big four athletes in this division.    THEMAT.COM RANKINGS FOR APRIL 2004  60 KG/132 LBS. IN GRECO-ROMAN  1. Jim Gruenwald, Colorado Springs, Colo. (Sunkist Kids)  2. Glenn Nieradka, Colorado Springs, Colo. (U.S. Army)  3. Joe Warren, Colorado Springs, Colo. (New York AC)  4. Jacob Hey, Colorado Springs, Colo. (U.S. Air Force)  5. Willie Madison, Metairie, La. (USOEC/Gator WC)  6. Marco Lara, Tanstaa, Fla. (New York AC)  7. Alex Pashkov (New York AC)  8. Nathan Piasecki, Marquette, Mich. (USOEC/Gator WC)  9. Matthew Birner, San Diego, Calif. (U.S. Navy)  10. Jason Chao, Colorado Springs, Colo. (Gator WC)    ATHLETES ALREADY QUALIFIED FOR THE OLYMPIC TEAM TRIALS   Armed Forces Champion  - Glenn Nieradka, Colorado Springs, Colo. (U.S. Army)  West Regional Trials Champion - Jason Chao, Colorado Springs, Colo. (Gator WC)  North Regional Trials Champion -John Habeck, La Crosse, Wis. (Eagle)   Central Regional Trials Champion -Jason Tolbert, Colorado Springs, Colo. (U.S. Army)