KEY BISCAYNE, Fla. -- When you've played professional tennis for 18 years, it's easy for people to start thinking of you in past tense instead of present.
Just don't make that mistake with Andre Agassi. The amiable, thoughtful and frequently charming Agassi turns sharp and short at questions hinting at his retirement.
See, he's not ready to go. A 6-2, 7-6 (2) loss to Agustin Calleri in the fourth round of the Nasdaq-100 Open when the guy's playing out-of-his-head tennis is just not a huge worry to Agassi.
"Guys hit the ball big now," Agassi said. "Anything can happen if you're not careful, if you're not playing your top game."
Vince Spadea, who defeated Paradorn Srichaphan 5-7, 6-3, 6-2, will face Calleri next and said he thought Agassi seemed a little surprised at how well Calleri played.
"Every time you play a guy, you know people improve," Spadea said. "Even Paradorn improved from the last time I played him."
"So, that's why no matter what your record is against a guy, you got to be ready."
Andy Roddick, who managed a 6-3, 6-3 victory against Guillermo Canas, said Agassi's upset does emphasize that no match is routine.
"We don't just say it to say it; that's for sure," said Roddick, who plays No. 5 seed Carlos Moya next. "You can't go into a match, you know, expecting to win. You can go in a match to win it. But nothing's a given out here that's for sure."
For Agassi, the loss ended a 19-match win streak dating back to 2000. He's won at this venue six times, one more time than his wife, Steffi Graf. A total of 57 match wins. And he can still recount the first loss off the top of his head. So don't think losing this time doesn't mean something.
But for those who think he's chasing history, he says instead, he plays because he can.
"I don't think it's about the accomplishments that keeps me out here," he said. "It's about pushing myself to get better and still feeling like I can do that, still feeling like I can win if I play my best tennis."
He's cut back on events. He no longer plays Davis Cup because two ties are played after Grand Slam tournaments, another follows this tournament, considered the biggest after the Slams, and one at the end of the year following Masters Cup. That's a lot of tennis in a row for almost 34-year-old legs.
"I'm trying to give as much to the game that I can for as long as possible," Agassi said. "I just don't want to burn the candle at both ends. It's not something that makes sense for me."
He did allow one consideration of the future that happened to involve Davis Cup. Could he one day see himself as captain of the U.S. team?
"I don't know," he said. "I love the fabric of tennis, you know, the fundamentals of it, the talking about it, the interaction with it. Coaching is something that is to the heart of what it is I enjoy.
"I enjoy learning about the game, learning about players. So, I would never say that I wouldn't be excited to do it because it would be a tremendous, tremendous honor."
Even what tennis Agassi does play is more than 21-year-old Roddick can imagine doing at that age.
"No," Roddick said, laughing. "Thirty-four, I'm going to be eating Cheetos and watching football."
Coming into this tournament, Agassi had reached three consecutive semifinals: Australian Open, San Jose and Indian Wells. At the same time last year, he'd won the Australian, lost in the first round at Scotsdale, skipped Indian Wells and won this event.
He would win only one other tournament, on the clay in Houston, the rest of the year, but reached the semifinals at the U.S. Open and Masters Cup.
Some think his fitness is one of his biggest advantages early in the year when some players are coming off the short layoff over the holidays.
"When I came out [on the tour], they considered me the hardest-hitting player," Agassi said. "I hit the ball so hard. Now, it's - that's not what makes me better than some guys; it's other things. Because everybody hits the ball so well.
"I think I've gotten to be a better athlete. I've gotten stronger. I think I've had the ability to handle the pace of the game and the improvements in the game. … So it's kept me close."
Cynthia Faulkner is the tennis editor for ESPN.com.