His suspicions were confirmed Tuesday night.
Cano and Kyle Seager had three RBIs apiece, Jones added two more and a seven-run sixth inning propelled the Mariners to score a season high in a 13-2 win over the Houston Astros, giving Seattle its second straight game scoring in double digits.
Cano drove in two runs to give Seattle the lead in the first and hit the first of the five doubles in the sixth inning that tied a franchise mark and pushed the lead to 10-1.
Jones' three hits included a triple. The rookie, who hits in front of Cano, has seven hits in the first two games of this series. The Mariners won the opener 10-4.
''I was telling Howard (Johnson), the hitting coach: `We've been winning games and he's not getting on base,''' Cano said. ''Watch how many runs we're going to score when he starts getting on base.' And look what happened the last two days.''
Manager Lloyd McClendon has been impressed with the Jones' progress.
''He's getting a lot of big hits for us, he's hitting left-handers, he's running the bases well,'' McClendon said. ''I've been very pleased. He continues to get better every day.''
Hisashi Iwakuma (6-4) went six innings, giving up a run on seven hits while striking out seven as the Mariners improved to eight games over .500 for the first time since the end of the 2009 season.
Seager doubled and hit a solo homer in the ninth as the Mariners also set a season-high with 18 hits.
Jarred Cosart (8-6) tied a season-high by allowing six runs on nine hits with four walks in 5 2-3 innings to end a four-game winning streak.
''A lot of pitches up in the zone,'' manager Bo Porter said. ''When he was on the streak that he was on, he was really finishing his breaking ball and inducing weak contact, but today, there were just a lot of pitches up in the zone.''
Darin Downs relieved Cosart and allowed five consecutive hits, with four doubles.
All of the Mariners' runs in the sixth came with two outs to mark the first time they've had six straight run-scoring hits with two outs in an inning in franchise history, according to STATS. It's also the first time they've scored at least 10 runs in consecutive games since June 19-20, 2012.
Jones singled in his first two at-bats to give him a hit in six straight plate appearances. He had an RBI in the second and his second one in the seventh made it 11-1.
Domingo Santana, Houston's eighth-rated prospect by Baseball America, went 0 for 4 in his major league debut after being called up from Triple-A Oklahoma City on Monday. Santana reached on an error in the seventh inning and scored on a ground-rule double by fellow rookie Kike Hernandez. Santana is the last of the players from the 2011 trade with the Phillies for Hunter Pence to reach the majors, joining Cosart, Jon Singleton and Josh Zeid.
Cano hit a two-run double with two outs in the sixth inning to chase Cosart and push the lead to 5-1. Downs came in and was greeted with three straight doubles: by Seager, Logan Morrison and Mike Zunino to score three more.
Endy Chavez drew a leadoff walk before consecutive singles by Jones and Cano made it 1-0 in the first. Jones scored on a groundout by Seager to make it 2-0.
Altuve and Presley singled in the first for Houston before Dominguez cut the lead to 2-1 with his two-out single to center field.
Ackley snapped an 0-for-21 skid with a single with one out in the second and scored on a single by Jones to make it 3-1. Ackley tied a season-high with three hits.
Hernandez, who was called up from Oklahoma City on Tuesday, made his major league debut when he entered the game at second base in the seventh inning and finished with two hits.
NOTES: The series wraps up Wednesday when Seattle's Chris Young opposes Brad Peacock. ... The Astros on Tuesday signed OF Derek Fisher, who was the 37th overall pick in the draft. ... Houston placed CF Dexter Fowler on the disabled list retroactive to June 27 with a back strain. He is hitting .270 with six homers and 24 RBIs.