Gio Gonzalez arrived in Yankees camp Tuesday, threw a bullpen session Thursday and, according to the veteran left-hander, will face the Phillies on Saturday.

Not only is Gonzalez competing against the clock after signing a minor league deal that has an April 20 opt-out clause, he has Luis Cessa, Jonathan Loaisiga and Domingo German to deal with.

Listening to Brian Cashman talk Thursday in Jupiter where the Yankees lost to the Cardinals, 11-3, they represent a strong challenge for the 33-year-old Gonzalez.

“Optimally, I would like to have the kids we have and rely on those guys, to be honest. We really do believe in the ceilings of the Cessas, Loaisigas and Germans. They have earned the opportunities and they are going to get those opportunities,’’ Cashman said Thursday before German gave up five runs and six hits (three homers) in 3 ²/₃ innings.

According to the general manager, Gonzalez was available and signed to add rotation protection.

“There was a guy like Gio sitting out there and we swung through to see if he wanted to come in here and be part of insurance in case things go wrong,’’ Cashman said. “But he has to compete to put himself in the best position to be a legitimate option. We will evaluate that over the coming month and see what happens. But personally we love to reinforce with our kids and give them the opportunity.’’

Gonzalez, who is 127-97 with a 3.69 in 313 games (303 starts), has more experience than the three right-handers and did go 3-0 with a 2.13 ERA in five starts for the Brewers late last year. But Cessa, Loaisiga and German have been in camp since the start and the Yankees’ brass is a lot more familiar with them than Gonzalez.

“But if [opportunity for the three] doesn’t exist and [Gonzalez] puts himself in the mix, then we will have decisions to make. That is why he is here. He is going to get a real fair look and free look as will we,’’ Cashman said of Gonzalez. “It is important to get into camp early, on time for you to have legitimate chance to force your way on. The other guys were here, so that is who we are focused on. If Gio sneaks up on us that can be a great story, but that is a story for down the line.”

After watching Gonzalez throw in the bullpen Thursday, pitching coach Larry Rothschild said his offseason work has put him in position for a game.

“He is pretty close to be ready right now,’’ Rothschild said “From our conversation he is throwing up to 100 pitches in [simulated] games. He faced hitters the last time on Monday and [Thursday] was a normal [bullpen] for him so we will see.’’

As for the bullpen session which Rothschild monitored from near the plate, he barked “real good’’ several times.

“I don’t get overly pleased on sides. It was good to see his arm working and things like that but a side is a side,’’ Rothschild said.

One that included a cut fastball that Gonzalez started toying with this winter while working out at the University of Miami. Gonzalez noticed the pitch has treated CC Sabathia well in recent years but said the idea to incorporate it didn’t come from a drastic drop in velocity (91 mph last year) as was the case with Sabathia. Instead it was more about adding a pitch.

“For me it was knowing at some point you have to change it up. I figured it would be the perfect pitch to work with. You see some of the young guys using it a lot and CC throws it as much as he can,’’ said Gonzalez, who went a combined 10-11 with a 4.21 ERA in 32 starts for the Nationals and Brewers last year. “There are some veteran guys who have done this for years.’’

— George A. King III reported from Tampa, Joel Sherman from Jupiter