Jeff Weaver decided not to return to St. Louis when he accepted a more lucrative offer Friday from the Seattle Mariners, according to sources familiar with the situation. Weaver, the last attractive free-agent pitcher other than Roger Clemens, jumped at an offer that guarantees him a base $8.325 million salary plus a series of appearances incentives worth potentially an additional $1 million. The deal will be announced Monday in Seattle after Weaver passes a team physical, a source said Friday night.