Aybar's fielding percentage also fell by 20 points, to .963, as his errors rose from 11 in 2010 to 21 while playing almost an identical number of games -- 136 in 2009, 135 in 2010.
Morales, whose season ended with a leg fracture on May 29, agreed to a one-year deal worth $2.975 million plus a $50,000 bonus for at least 550 plate appearances. The first baseman earned $1.2 million in 2010 in the final year of a six-year deal he signed after defecting from Cuba in 2004.
The agreements with Kendrick and Willits were reported by the Los Angeles Times.
Kendrick, who earned $1.75 million in 2010, was one of the most durable and productive of the Angels. Playing 158 games, the second baseman drove in 75 runs while batting .279 and delivering 251 total bases, six fewer than team leader Torii Hunter.
Willits, who reached a $625,000 agreement last year, batted .258 with a .341 on-base percentage in 159 at-bats as a spare outfielder.
Arbitration-eligible players need at least three years of Major League service and fewer than the six years required for free agency. If the two sides don't reach agreement, the case goes to an independent arbiter to decide.
Weaver reportedly filed for $8.8 million, with the club offering $7.365 million. Napoli is seeking $6.1 million; the team's proposal is $5.3 million.
Weaver, who made $4.27 million last season, could more than double that figure following a breakout year in which he led the Majors in strikeouts and was among the leaders in a number of other categories, including starts (34), innings (224 1/3) and ERA (3.01). The club averaged only 3.82 runs in his starts, largely accounting for his deceiving 13-12 record.
Napoli claimed a $3.6 million deal last winter and could reach about $6 million -- a hefty salary for a player who will be competing for a regular job behind the plate. Napoli produced big power numbers (26 homers, 24 doubles in 453 at-bats) and enhanced his market value -- and trade appeal -- by branching out and playing a capable first base in Morales' absence.