SEATTLE — Chicago Cubs reliever José Cuas hadn’t been fooling many hitters this season.

Since tossing 1 1/3 shutout innings with two strikeouts March 30 in Arlington, Texas, Cuas wasn’t effective. He surrendered at least one run in each of his last four appearances, giving up eight runs and 10 hits in 4 2/3 innings. Cuas also allowed both inherited runners to score and hit three batters.

The Cubs optioned Cuas to Triple-A Iowa on Thursday’s off day and recalled Keegan Thompson from Iowa before Friday’s series opener against the Seattle Mariners. Manager Craig Counsell cited Cuas’ predictability as a focal point he will need to work on in Triple A. It comes down to being more confident in the pitch he throws.

“He worked really hard to add the slider and then what happens is you get into the heat of the battle and you kind of go back to what’s comfortable and the hitters kind of made him pay for that essentially as outings kept stacking up a little bit,” Counsell said Friday. “These hitters are really good. They need to have doubt in their head and José needs to create that doubt. When he does he gets people out.”

Thompson, 29, had pitched well in his last three appearances for Iowa after getting roughed up in his season debut. He has given up only one hit in five shutout innings since then with two walks and six strikeouts.

“Clearly he has experience here in the big leagues, so it’s doing what he does well,” Counsell said.

Following Monday’s ugly outing he when was tagged for four hits and four runs in one-third of an inning en route to the Cubs blowing an eight-run lead to the San Diego Padres, Cuas said he has been attacking the strike zone and feels his slider is there.

“My four-seam (fastball) is up in the zone as opposed to middle, my sinker I’m locating it on the corners instead of middle, things like that — I just have to get back to watching some film, seeing where I’m missing and making those adjustments,” Cuas said Monday.

The Cubs acquired Cuas, 29, at the trade deadline last year from the Kansas City Royals for outfielder Nelson Velázquez. Cuas was valuable in a worn-down bullpen the last two months, posting a 3.04 ERA in 27 games.

Their bullpen depth is being tested with right-hander Julian Merryweather sidelined on the injured list and right-handers Javier Assad and Ben Brown shifting into the rotation because of injuries to Justin Steele (left hamstring strain) and Jameson Taillon (back strain). Taillon threw 3 2/3 shutout innings Friday night in his second rehab start and first with Iowa. He gave up three walks, one walk and struck out four batters on 68 pitches (46 strikes).

As for whether Taillon could come off the IL if his start went well, Counsell replied, “I’d like to solve the ‘if.’”

“I think (Saturday) is a good time for that question,” he said. “Let’s see how everything goes (Friday) with our team and Jameson’s start.”

Steele threw off a mound in San Diego and will repeat that during the Cubs’ series next week in Arizona as he keeps ramping up the intensity.

“We’re moving forward,” Counsell said. “We’re a little over 15 days or 16 days into this, so we’ve got a ways to go here still, but we’re making progress.”