PEORIA, Ariz. -- Before camp opened, we made predictions on which 25 players would crack the Mariners' Opening Day roster. For most of the spring, those forecasts looked pretty solid.
But general manager Jerry Dipoto and his staff made a few surprising moves that few saw coming, and some late injuries played a hand as well. Here's how the roster will look when Seattle opens its season Monday in Houston, as well as how things changed in a few key spots.
Catcher:Mike Zunino and Carlos Ruiz. No drama here, as Zunino and Ruiz have formed a pretty solid backstop duo. Zunino had an excellent spring, both at the plate and behind it, and Ruiz has brought an impressive veteran presence and wealth of experience.

First base:Danny Valencia. Here's where things start to change. The wide-spread assumption was rookie Daniel Vogelbach would split duties with Valencia in a platoon situation, but he wound up getting sent down to Triple-A Tacoma after hitting a rough stretch at the plate midway through spring. The feeling is Vogelbach will be better off continuing his development in the Minors, while the veteran Valencia -- who hasn't hit particularly well this spring either -- has the offensive track record to get the job done on a daily basis and is better defensively as well at this point.
Second base: Robinson Cano You expected anything different? Cano missed a big chunk of camp while playing in the World Baseball Classic, and then sitting out five days with the flu, but he appears poised for another big season.
Shortstop: Jean Segura. He's been everything expected this spring, a very good hitter with quick hands at the plate and a nice combination of speed and power, as well as a solid defender.
Third base: Kyle Seager. Mr. Dependable will hold this position as long as he's healthy.
Utility: Taylor Motter: We predicted Shawn O'Malley would win this job initially, then switched to Motter in a mid-camp update. As it turned out, the competition ended when O'Malley needed an appendectomy and won't be healthy by the start of the season. Motter showed everything the Mariners were looking for with a solid right-handed bat, some speed on the bases, the versatility to play every position and a strong throwing arm that makes him a legitimate outfield option as well.

Outfield: Jarrod Dyson, Leonys Martin, Mitch Haniger, Nelson Cruz and Guillermo Heredia. This was the five we predicted, and that played out as Haniger had an exceptional spring and left no doubt that he deserves the every-day job in right field. Heredia won the backup role with a solid camp as well. Ben Gamel made things competitive with a strong finish, but Heredia is a quality defender and showed improvement at the plate as well.
Starting pitcher: Felix Hernandez, Hisashi Iwakuma, James Paxton, Ariel Miranda and Yovani Gallardo. Another spot with a surprising late change, this one due to an arm injury to Drew Smyly. That opened the door for Miranda to be recalled, and he'll open the season as the No. 4 starter. Hernandez had a strong spring, as he heads for his ninth straight Opening Day start, and Paxton appears poised for a good year. But Iwakuma and Gallardo were inconsistent, and both are eager to move on to regular-season games to find out where they really are outside the difficult Arizona environs.

Bullpen: Edwin Diaz, Nick Vincent, Evan Scribner, Dan Altavilla, Casey Fien, Marc Rzepczynski, James Pazos and Dillon Overton. Not only did some of the names change in the bullpen mix, but the Mariners will carry eight relievers instead of the expected seven, which became possible when Vogelbach was sent down and the first-base platoon became a one-man show. We initially expected Shae Simmons and Miranda to be in this group, but Simmons is dealing with a strained forearm and Miranda wound up being needed in the rotation. Fien and Pazos took their places, and the club added Overton as an extra arm -- at least to open the season. Pazos, Altavilla and Overton are all rookies.
Overton is officially on the 25-man Opening Day roster, but he could be replaced for several days and given paternity leave as his wife is scheduled to have their first child on Tuesday.