It was the sort of choice NFL personnel guys dream about.

With the 13th pick in the 2003 NFL Draft, the Patriots were looking at plenty of options. For a team that struggled to stop the run the year before, there appeared to be a bunch of really good defensive linemen, including Ty Warren from Texas A&M. And for a secondary in a state of flux, there were a lot of good defensive backs, including USC safety Troy Polamalu, a first-team All-American. Warren or Polamalu? It figured to be a win-win either way.

In the end, the Patriots went with Warren, and the decision was certainly a good one. Six seasons later, when compared to many of the defensive linemen taken in the first round that same year (Johnathan Sullivan? Dewayne Robertson?), Warren has become a steady and solid presence along New England’s defensive front, combining with Richard Seymour and Vince Wilfork to create one of the best front threes in the league.

A high character guy, Warren has 19.5 career sacks. According to Mike Tanier of FootballOutsiders.com, in 2007, Warren led all Patriots linemen in stops (a tackle near the line of scrimmage). While he only recorded four sacks in 2007, he was third on the team with 13 hurries and led the team with 12 quarterback knockdowns.

“This past year, his numbers appear to be down, but a lot of that has to do with the groin injury,” Tanier said. “He only really played 10 games, plus bits of three others.”

But the thought of Polamalu in New England? The mind reels at the possibilities. And if the Patriots hadn’t gone out and gotten themselves Rodney Harrison in free agency a month before the 2003 draft, New England might have had their focus on Polamalu. (The Steelers traded up to get Polamalu with the 16th overall selection.) A smart player who has never gotten in trouble and has shown a proclivity to play through pain? Sounds like a Belichick guy.

“He is very fast, quick, is a tough guy, good tackler, very aggressive and is very instinctive,” Belichick said when asked about Polamalu late in the 2008 season. “He really has a nose for the ball. He has a good level of anticipation on what is going to happen. I would say that he is a guy that, whenever he is on the field, you have to be aware of him.”

However, New England signed Harrison a month before, leaving us to wonder what might have been. On the field, it’s no a stretch to say that the Patriots secondary would have looked an awful lot like it does now: Since 2003, Harrison has 442 tackles, while Polamalu has 433. Harrison has nine sacks, Polamalu has seven. Both are around the ball an awful lot for a safety — Harrison has eight interceptions, while Polamalu has 17. And Harrison has a pair of Super Bowl rings, while Polamalu could gain his second this weekend if Pittsburgh beats Arizona in Super Bowl XLIII.

In addition, other stats look alike: according to Tanier, Polamalu’s average tackle on a running play occurred 4.9 yards downfield, while Harrison was 5.5 yards downfield. (Both numbers are among the best in the league for safeties, a position that features a lot of “clean-up” tackles after 20-yard gains.) In 2007, Polamalu registered 16 defeats (a tackle for no gain or a loss or a third-down stop), while Harrison had 15.

But Belichick said their similarity isn’t just seen in the numbers.

“They make plays in every aspect of the game,” Belichick said when asked to compare Harrison and Polamalu. “They blitz. They tackle. They cover. They knock balls down. They intercept them. They play with great emotion, competitiveness and toughness. They take on anybody — guards, tackles — it doesn’t matter who it is. They’ll hit anybody, whoever is there. They will hit them just as hard — it doesn’t make a difference of how big they are or what number they are wearing. I think there are a number of similarities in those two players.”

Harrison’s veteran presence was integral in helping a crew of relatively young defensive backs make it through the 2003 season. And Tanier said the presence of Polamalu in the secondary would have given New England a boost this past season. But overall, Tanier says the move to take Warren ahead of Polamalu was the better decision. While Polamalu may have generated more big plays in the Patriots’ defense the last few seasons, Warren’s consistent presence has turned out to be a great fit in New England’s defense, and a better long-term investment for the Pats.

“[Polamalu] might have generated a few more big plays than Harrison, and he would have missed fewer games with injury, [but] the improvement at safety would be slight,” Tanier said. “Meanwhile, the difference between Warren and a lesser lineman would have hurt the Patriots run defense significantly and their pass rush a little.

“The upgrade to Polamalu over Harrison wouldn’t be as great as the upgrade to Warren over an average defensive lineman.”