BOSTON (AP) _ As the Red Sox introduced Mark Portugal, the newest addition to their pitching staff, the question still lingered: Who will replace slugger Mo Vaughn?

With Portugal, who was 10-5 with Philadelphia last season, the team has secured a fourth starter in their rotation of Pedro Martinez, Tim Wakefield and Bret Saberhagen.

But the real concern for the team is how to fill the void of Vaughn, although general manger Dan Duquette isn't worried.

``We don't have Mo Vaughn's power, but we have (recently signed Jose) Offerman's on-base capability matching Vaughn's,'' Duquette said. ``The good news is we got Mark signed and the bulk of the pitching staff back.''

Portugal agreed to a $2.7 million salary in 1999 and a club option at $3.3 million in 2000 with a $300,000 buyout.

``Mark is a proven veteran starting pitcher,'' Duquette said. ``He has won up to 18 games, has a good changeup and excellent control. We like his overall leadership.''

Portugal returns to the American League, where he last pitched for Minnesota in 1988. Since then, he played for Houston, San Francisco and Cincinnati before spending the last two seasons with Philadelphia.

He pitched his last game in 1997 on May 3, then underwent elbow surgery that sidelined him for the season. But he pitched 166 1-3 innings last season.

Portugal has a 102-83 record and a 3.89 ERA for his career.

``Rehab is not a fun process and I've been through a few of them,'' Portugal said. ``I'm just looking forward to getting back out there now.''

His best season was 1993, when he was 18-4 with a 2.77 ERA for Houston.

Portugal wanted to play for Boston, in part because his children, Derrick, 9, Jacob, 6 and Alexandra 3, live in Rhode Island.

``They wanted me to go to St. Louis because they want to meet `Mac', but they're going to have to settle for Nomar,'' Portugal said. ``They've just become the biggest Red Sox fans in all of New England.''

Nomar Garciaparra is Boston's top remaining hitter, coming off a season in which he batted .323 with 35 home runs _ half of Mark McGwire's total for St. Louis _ and 122 RBIs.

When Portugal tried on his new Red Sox shirt, he joked that there was no No. 21 _ the number that Roger Clemens wore while pitching for the Red Sox.

Portugal's comment echoed rumors that the Red Sox were interested in the five-time Cy Young Award winner, who demanded a trade to a contender or to a team closer to his Houston home.

Duquette said Boston has made some ``aggressive offers'' for Clemens, but he was not hopeful The Rocket would return to the Red Sox.

``We're not encouraged by what we've heard from Toronto,'' Duquette said.

Duquette was also not confident about finding a replacement for Vaughn at the general manager's meetings in Nashville, Tenn., this weekend.

``I don't know,'' Duquette said. ``We've had some great discussions we're going to follow up on.''

``I wouldn't be too worried about it, we still have our core players. As I said, we've still got an ace pitcher, closer and the best shortstop going,'' Duquette said. ``We don't open up until April 1.''