Estrada (back) was released by the Athletics on Tuesday, Martin Gallegos of MLB.com reports.

EDGE Analysis

Estrada was on the 60-day injured list due to a back strain, and after struggling through his last three rehab outings, he's been issued his release. The veteran right-hander accrued an unimpressive 6.85 ERA and 1.31 WHIP with 11 strikeouts over five starts with Oakland this season (23.2 innings), and he hasn't pitched in the big leagues since April 16.

Estrada (back) allowed four earned runs on four hits and three walks while striking out three over three innings for Triple-A Las Vegas against Albuquerque on Friday.

EDGE Analysis

The veteran right-hander was making a big leap in competition from the High-A level, and he ran into plenty of trouble during his relatively brief time on the mound. Estrada surrendered a solo home run to Sam Hillard and a double to Drew Weeks in terms of extra-base hits, pushing his ERA to 8.44 across 10.2 innings during his rehab assignment. It's uncertain where the Athletics go from here with Estrada, as he appears close to stretched out (59 pitches Friday), but he's also proven ineffective over his last three rehab outings.

Estrada (back) will make his next rehab start with Triple-A Las Vegas on Thursday, the Associated Press reports.

EDGE Analysis

The move up to the Aviators is somewhat surprising given how Estrada struggled against High-A hitters in his appearance for Stockton last Friday. Nevertheless, the Athletics will give the veteran right-hander a whirl against a notably higher caliber of competition. Estrada owns a 7.04 ERA, 1.30 WHIP and .273 BAA across 7.2 innings over four rehab starts thus far.

Estrada (back) allowed three earned runs on five hits, a walk and a balk over 2.2 innings in High-A Stockton's loss to Rancho Cucamonga on Friday. He struck out four.

EDGE Analysis

Estrada worked up to 55 pitches, 35 of which he got into the strike zone. The fact the veteran right-hander was so hittable was certainly concerning when considering the quality of competition he faced, and the outing marked the second consecutive in which he's allowed multiple earned runs. Estrada figures to continue toiling away in the lower levels of the minors for at least one more rehab appearance before any move up is considered.

Estrada (back) struck out two in a scoreless inning for the Arizona League Athletics on Thursday.

EDGE Analysis

Everything apparently went off without a hitch in what was Estrada's first game action since April. According to Susan Slusser of the San Francisco Chronicle, the veteran hurler is scheduled to make his next rehab appearance for High-A Stockton on Tuesday. It remains to be seen how long Estrada will spend rehabbing in the minors.

Estrada (back), who still isn't cleared to throw regular bullpen sessions, could be in the minor leagues until rosters expand in September, Martin Gallegos of MLB.com reports.

EDGE Analysis

The veteran right-hander appeared to be trending in the right direction in late June, when it was reported he'd completed a 25-pitch bullpen session without setbacks. At that point, it was believed that Estrada could embark on a recovery timeline that would make him available shortly after the All-Star break, but Gallegos essentially reports that's no longer the case. Estrada would still need to throw multiple bullpen sessions within relatively close proximity and then eventually embark on a multi-appearance rehab assignment. Given the timing, it appears increasingly likely the veteran right-hander may not be summoned back to the majors until the final month of the season.

Estrada (back) was transferred to the 60-day injured list Tuesday.

EDGE Analysis

The move has no effect on Estrada's timeline, as he's already been out for more than 60 days. He's expected to return to the Athletics' rotation at some point soon after the All-Star break. The transaction clears a spot for Oakland to activate Chris Herrmann (knee) from the injured list.

Estrada (back) completed a 25-pitch bullpen session Saturday and relayed that he felt "OK" afterward, Susan Slusser of the San Francisco Chronicle reports.

EDGE Analysis

While Estrada wasn't overly positive about his first mound work since undergoing a procedure in April to alleviate back pain, the Athletics were likely satisfied with the fact that the 35-year-old took a step forward in the rehab process. According to Slusser, Estrada's prior experience with rehabbing back injuries (and perhaps his status as a pending free agent) could prompt the Athletics to take an aggressive approach with his recovery, even though he's been sidelined for more than two months. Prior to getting shut down, Estrada managed only a 6.85 ERA and 1.31 WHIP in five outings, but he should be assured a rotation spot if he's able to return shortly after the All-Star break. An already-weak Oakland starting staff suffered a major blow Friday, when ace Frankie Montas was suspended for the rest of the season.

Estrada (back) threw 15 pitches from flat ground Thursday and could toss a bullpen session as soon as Saturday, Martin Gallegos of MLB.com reports.

EDGE Analysis

Estrada was restricted to throwing fastballs from flat ground Thursday, but he could take another step forward over the weekend, assuming he feels good following his latest throwing session. The right-hander still has a ways to go before embarking on a rehab stint, however, per Gallegos.

Estrada (back) completed a throwing session on flat ground Tuesday, Susan Slusser of the San Francisco Chronicle reports.

EDGE Analysis

Estrada continued with his throwing program as he makes his return from a back strain and the ablation procedure he underwent in April. The 35-year-old will need to advance to throwing off a mound before there's any real timeline for his return to the majors.