St. Louis ? If Ken Griffey Jr. can stay in the lineup, the next 100 home runs might come a lot easier than his 500th.

Of course, for Junior, that’s a big if.

“Knock on wood, he stays healthy,” Cincinnati manager Dave Miley said. “He’s swinging the bat well, he feels good, and that’s probably as big a key as anything for him.”

The 34-year-old Red, who Sunday became the sixth-youngest player to reach 500 when he snapped a weeklong homer drought, once seemed like a good bet to chase Hank Aaron’s record of 755 home runs. He was the youngest to 350 homers, 400 and 450.

But injuries have slowed Griffey since — he has averaged just 73 games and 14 homers the past three seasons.

“I don’t worry about the time that I missed,” he said. “When you play hard and you get hurt, that’s one thing. If I would have done it doing something else, then I could say, ‘What if?”‘

Perhaps the best player of the 1990s, he led the American League in homers from 1997-99 and won 10 straight Gold Gloves from 1990-99.

Then injuries began taking their toll. He missed more than a month with a torn hamstring that bothered him throughout the 2001 season, spent two long stints on the 15-day disabled list with a torn patella tendon and a torn right hamstring in 2002, then went to the DL twice again in 2003 for a dislocated right shoulder and torn ankle tendon.

The ankle injury ended his season July 18, limiting him to only 53 games.

This season, though, the pressure of No. 500 has been the only thing slowing down Junior. With 19 homers already, he’s on pace for 45 — just like the Griffey of old.

Now that the pressure of reaching 500 has been alleviated, those closest to Griffey are anticipating more vintage production.

“He’ll be a lot more relaxed now,” his father, Ken Griffey Sr., said. “I’m just thinking about him staying healthy and seeing what happens after that.

Cincinnati Reds center fielder Ken Griffey Jr. (30) and his father, Ken Griffey Sr., hug as Junior's oldest son, Trey, looks on after Junior hit the 500th home run of his career. Though he has been hampered by injuries in recent years, Ken Griffey Jr. tagged No. 500 on Sunday in St. Louis.

“If he stays healthy the next six or seven years, there’s no telling.”

There is recent precedent for a player in his mid to late 30s putting up big power numbers. Barry Bonds hit 73 homers at age 37 in 2001, and Mark McGwire hit 70 in 1998 when he was 35 and 65 the following season.

Before his three injury-riddled seasons, Griffey averaged 50 homers and 137 RBIs the previous four years. If he had stayed healthy, Griffey may have hit 500 two years ago.

“An achievement like that deserves a lot of credit and a lot of respect,” Cardinals manager Tony La Russa said. “He has missed a lot of at-bats, or he would have been there sooner.”

But Griffey has no regrets, especially since his injuries have resulted from his hustling style of play.

“I go out there with one goal, and that’s to play as hard as I can,” he said. “If that means running into a wall, I’ll run into a wall. If that means dive, I’ll dive. That’s just how I was raised, to go out there and play 100 percent and whatever happens, happens.”