MARINERS 7, CUBS 3 CUBS 3, ROCKIES 0

Surprise decision

In the surprise decision of camp, the Cubs said Saturday they’ll open the season with

Victor Caratini as their backup catcher, sending veteran Chris

Gimenez to Class AAA Iowa. ‘‘ The biggest thing is we felt that Victor’s ready for this,’’ manager Joe Maddon said of the switch- hitting Caratini, who was pressed into a big- league debut last June, when veteran

Miguel Montero was released after making critical comments about teammate Jake Arrieta. ‘‘ But we also know that he may not get enough opportunity to play in the beginning. However, even possibly sitting there, going through the prep every day and getting in some action on occasion — maybe pinch- hitting once in a while, picking up some later innings — is that equally valuable for him to go back to Triple- A, where he’s done a really good job in the past and you know he can do that? That was part of the argument.’’

Caratini was always considered the better offensive choice.

All set?

The catching decision all but sets the roster. The only possible decisions left involve whether reliever Pedro Strop ( made only third appearance Saturday because of an early calf injury) is ready to open on time and whether the Cubs decide a low- level waiver move in the next few days might strengthen the final bullpen spot.

Lester ready

Left- hander Jon Lester pitched three innings against minorleaguers in a 57- pitch tuneup for the regular- season opener Thursday. ‘‘ Today was just more trying not to die,’’ said Lester, who accomplished that.

On deck

Cubs at Royals, Surprise, Kyle Hendricks vs. Ian Kennedy, 2: 05 p. m. Sunday, Ch. 9, 670- AM.