The back problems plaguing Toronto Blue Jays right-hander Marco Estrada - which, in July, forced him to the disabled list for about three weeks - are reportedly more serious than the club and its ailing 33-year-old have led on.

Estrada, who owns a 5.47 ERA in 10 starts since returning from the disabled list July 22, has been pitching with a herniated disk in his back, according to Jon Morosi of MLB Network - the same injury that sent Clayton Kershaw to the disabled list for more than two months earlier this year.

Though his second-half slide continued in Wednesday's 8-1 loss to the Tampa Bay Rays (his auspicious start notwithstanding), Estrada didn't note any back discomfort after coughing up four runs on four hits and three walks over 5 1/3 innings at Rogers Centre.

"I still felt like I threw the ball really well," Estrada told MLB.com. "Obviously, it didn't look all that great out there, but it's basically just one inning. I've just got to put it past me. I like where I'm at, I like where my pitches are. It's just a little bit of bad luck, I guess."

Still, while bad luck may have contributed some to Estrada's recent woes - over his last six starts, for instance, his batting average on balls in play is .333 - his peripheral numbers have tailed off dramatically since the All-Star break, too.

Split ERA WHIP K% BB% HR/9 1st Half 2.93 0.99 24.1% 9.5% 1.21 2nd Half 5.47 1.48 19.7% 7.9% 1.37

Before Wednesday's start, incidentally, Dioner Navarro - Estrada's recently repatriated personal catcher - was confident his batterymate would be able to get back on track.

"He's going to be fine," Navarro told Brendan Kennedy of the Toronto Star. "He's been here before. He knows how to deal with it."