Sandoval will receive a $3 million signing bonus. He will make $17 million a season from 2015-17, and then make $18 million in 2018 and 2019. The club option will be for $17 million, with a $5 million buyout.
Lucas hit .251 with one home run, five doubles and nine RBI in 69 games with the Marlins last season. He has a .255 average in 163 career MLB games.
Seager, 23, posted career highs in home runs (25), RBI (96), batting average (.268), slugging percentage (.454) and OPS (.788) in 2014. He has a .262/.328/.429 slash through his first four seasons in the majors.
Sandoval, who is a two-time All-Star, is a career .294 hitter in seven MLB seasons -- all with the Giants. He also has a career .346 on-base percentage, .465 slugging percentage and .811 OPS. He has totaled 106 home runs, 192 doubles and 462 RBI in 869 games.
The decision "looks like" it will be between the Red Sox, Giants and Padres, and all teams involved are believed to have been asked to submit final offers. Sandoval hit .279/.324/.415 with 16 home runs and 73 RBI in 588 at-bats.
The team is believed to have offered a five-year, $95 million deal to the 28-year-old. It was reported early in Sandoval's free agency that he was seeking a six-year contract, and it's unclear if any of his current offers contain an option for a sixth season. Sandoval hit .279/.324/.415 over 588 at-bats.
Urshela sprained his PCL, but the injury isn't as serious as expected. He should be ready to go for the start of 2015.
Along with the Padres, the Giants, Red Sox, White Sox and Blue Jays have also shown interest in signing the third baseman.
Williams was considered the Yankees' third-best prospect by Baseball America heading into the 2014 season.
Torreyes hit .298 with two home runs, five triples, 20 doubles and 46 RBI in 126 games last season for Triple-A Oklahoma City.
Velasquez went 7-5 with a 3.52 ERA in 18 appearances (13 starts) between Rookie League and high Class A last season.