Bob Welch, Fernando Valenzuela and Tom Brunansky were among 18 free agents offered salary arbitration Friday, allowing them to continue negotiating with their former clubs through Jan. 8.

Teams faced a midnight deadline to offer arbitration or lose the chance to re-sign their former free agents until May 1. Players offered arbitration have until Dec. 19 to accept or reject the offers, while those refused arbitration may not negotiate with their former clubs until after May 1.Also offered arbitration by their former teams were Donnie Hill and Max Venable (California), Dan Petry (Detroit), Bill Krueger (Milwaukee), Randy Bush (Minnesota), Scott Sanderson (Oakland), Craig McMurtry (Texas), Juan Agosto (Houston), Mickey Hatcher and Juan Samuel (Los Angeles), Dave Schmidt (Montreal), Gary Redus and Don Slaught (Pittsburgh), Denny Walling (St. Louis) and Dennis Rasmussen (San Diego).

Among those players not offered arbitration were: Willie Randolph (Oakland), Ken Griffey Sr. (Seattle), Charlie Hough (Texas), John Candelaria (Toronto), Jim Presley (Atlanta), Rich Mahler (Cincinnati), Glenn Wilson (Houston), Wally Backman and Rafael Belliard (Pittsburgh), John Tudor (St. Louis), Fred Lynn (San Diego) and Gary Carter (San Francisco).

In one deal Friday, infielder Fred Manrique agreed to a non-guaranteed $325,000, one-year contract with California. Manrique, 29, began the 1990 season with Texas, was traded to Minnesota in mid-April and finished the season in the minors.

Because many of the contracts agreed to this week have not been finalized, clubs offered arbitration to six players who already have reached tentative agreements, just in case they fall through: Dave Righetti (New York Yankees), Willie McGee (Oakland), George Bell and Rance Mulliniks (Toronto) and Sid Bream and Zane Smith (Pittsburgh).