They were two of the Bills' best players during their time in Buffalo, but circumstances made it impossible for them to finish their careers here.

Linebacker Takeo Spikes and cornerback Nate Clements return to the place where their star shined brightest when the San Francisco 49ers visit the Bills on Sunday.

"Looking forward to it," Spikes said this week during a conference call with the Buffalo media. "Just so much history. I think it was really the first place that I really could call home even since [leaving] just because I had so many good times and still talk to a lot of people there as well."

"I'm excited about it," Clements said during a phone interview with The News. "That's where it all began for me."

The last time Spikes and Clements played in Ralph Wilson Stadium they had the support of an adoring crowd. That may not be the case on Sunday.

Both players are curious how fans will react to them in a different uniform.

"I asked my father the other day, 'Do you think they will boo me?'" said Clements, who left town after receiving a contract that reportedly could be worth up to $80 million. "If they did, I understand. But I think it would be like 'We respect you, but you're on a different team so by default we have to boo you.' It wasn't like I ended on bad terms."

Spikes may play in San Francisco, but he sounds like his heart is still in Buffalo. He wanted to retire here. He said the people are genuine and he fondly recalled how Bills fans wooed him when he played his last game with the Bengals in the 2002 finale at The Ralph.

"It was almost like a recruiting trip coming out of high school going to college," said Spikes, who was traded to Philadelphia in 2007. "I saw the mock jerseys with 'Spikes' on it, saying 'Spikes, you're a free agent. We want you here.' Just to go through that process and just to see it come true, and then once I got there it was a great fit for me. To have the success that I had there as quickly as I did ... it just kind of affected everything else after that."

Like they were with the Bills, Spikes and Clements are stalwarts on the 49ers' defense.

Playing inside linebacker next to young superstar Patrick Willis, Spikes is the 49ers' second-leading tackler with 82 and has a team-high three interceptions. Clements, the 49ers' No. 1 cornerback, has posted 50 tackles with two interceptions and eight passes defensed in 11 starts.

"I think Nate is one of those guys that is a competitor," said head coach Mike Singletary. "You like what he brings to your defense. He brings toughness out there on the edge, he brings a competitiveness, he brings a work ethic. He just continues to get better. I look at Takeo and he just continues to be a bright spot. He provides leadership, a lot of heart and he just likes to play football. You like those guys on your team."

Clements and Spikes took different paths to San Francisco.

Clements joined the 49ers after signing the richest contract ever for a defensive back. It was a big payoff from six good years with the Bills, who made him their first-round draft pick in 2001.

Clements, who returned his first career interception off Peyton Manning for a touchdown, started 88 straight games and 91 overall for the Bills. The 2004 Pro Bowler registered 23 interceptions and set a club record with seven career touchdown returns (five interceptions, two punts).

The Bills made Clements their franchise player in 2006, but they allowed him to become a free agent after the season. That guaranteed his departure because the Bills weren't entering a bidding war to retain him.

"To be honest, I think they kind of knew that my market value was going to be too high for them to try to commit to me like that," Clements said. "No regrets, no animosity. I think they could have if they wanted to, but I understood why they didn't."

Clements had his second 100-tackle season to go with four interceptions, 18 pass breakups and three forced fumbles in his first year. But some Bay Area critics don't think he's been the consistent lock-down defender he's paid to be. They point to last week's loss at Dallas where Clements was victimized by Cowboys receiver Terrell Owens, who had seven catches for 213 yards, including three plays over 40 yards.

Despite that poor game, Clements hasn't lost any confidence. He loves the challenge of covering the opponent's best receiver, and he's motivated to redeem himself against Bills wideout Lee Evans on Sunday.

"Anytime you come off of a bad game you want to come back the next week and make a statement," Evans said. "That will definitely be his mind-set coming in and that's what good football players do, they come back and try to respond."

Spikes came to Buffalo with plenty of fanfare. His impact was immediate as he intercepted two Tom Brady passes in a season-opening 31-0 win over New England.

Spikes earned his only Pro Bowl invitations in 2003 and 2004, while averaging 127 tackles with seven interceptions, 20 passes defensed and five forced fumbles. But he missed the last 13 games in 2005 with a torn Achilles tendon and was limited to 11 starts the following year because of hamstring problems.

The Bills dealt Spikes to Philadelphia in March, 2007 as part of a trade that included defensive tackle Darwin Walker, who refused to report to Buffalo without a new contract and was eventually shipped to Chicago.

Spikes played well for 15 games, but missed the final game (against Buffalo) with a torn rotator cuff that required season-ending surgery. And despite being the Eagles' second-leading tackler with 139 stops, they released him last March.

There were doubts that Spikes would ever be the player he was before the injuries, which is why he takes a lot of pride in the productive season he's having.

"It was satisfying," he said, "and I'm loving every minute of it."

Spikes has enjoyed plenty of individual success, but what he craves most — the playoffs — continues to elude them. His 155 games without a postseason berth is the longest active streak in the NFL.

However, he hasn't given up yet.

"It's frustrating as hell, man," said Spikes, who turns 32 in December. "I try not to get caught up into 'Why me?' But when is it going to happen to me? It's going to happen. Lord knows, it needs to happen soon because my time is not what it used to be versus when I got to Buffalo. I just started the back nine [of my career]."