Josh Donaldson broke camp this spring as the A's starting third baseman. So it would be understandable if he took a little while to get himself going again after being sent down to Triple-A on April 23.

He did only go 3-for-11 in the three April games he played with Triple-A Sacramento. Of course, the three hits were two homers and a triple. However, that looks like a mammoth slump compared to what he's done since.

This past week, Donaldson went 10-for-19 over six games to earn Prospect Player of the Week honors. Two of those hits were homers and he slugged .842 for the week. Combined with his .609 OBP, he posted a staggering 1.451 OPS. Since he's been back down in Triple-A, Donaldson is hitting .500/.568/.974 with five homers and 14 RBIs in 11 games. He's had six multihit games in eight May contests.

A very strong argument could have been made to give the honor to Red Sox outfield prospect Jackie Bradley Jr. Bradley only had 12 official at-bats for the week thanks to six walks and three hit-by-pitches. Still, he managed a .583/.727/1.167 line for a 1.894 OPS in five games.

Padres' Portillo is Pitcher of the Week

In his April 27 start against Burlington, Padres prospect Adys Portillo (No. 17 on San Diego's Top 20 Prospects list) gave up four runs on six hits over just four innings. He no doubt wanted to improve on that in his next two Midwest League outings.

The 20-year-old Venezuelan right-hander did that and then some, tossing 14 shutout innings to earn Prospect Watch Pitcher of the Week honors.

Portillo gave up just three hits combined in the two starts, going seven innings in each, and holding opposing hitters to a .067 average. He struck out 12, but even more importantly, he walked only three.

Portillo has struggled with his command in the early stages of his career and he had issued 14 walks in his first 24 1/3 innings. This is the right-hander's second long taste of life with Class A Fort Wayne. In 2011, he walked six per nine innings. His two most recent starts lowered his season rate to 4.0 -- a step in the right direction.

Portillo is third in the Midwest League with his 1.41 ERA and is tied for third in strikeouts, with 38. He's held hitters to a miniscule .140 average and kept his WHIP down to 0.91 (good for fourth in the league) thanks to that reduced walk rate.

A's prospect Cabrera dealing with back issue

Oakland shortstop prospect Yordy Cabrera said his work in extended spring camp has been beneficial. He's just ready to move on.

Cabrera, ranked no. 8 on the list of Oakland's Top 20 prospects, said his back locked up during Spring Training and he was later diagnosed with a stress fracture in his spine. He has been rehabilitating his back in Phoenix and could be on his way to advanced Class A Stockton. There is an outside chance he will end up in Class A Burlington.

"I really don't know how it happened," Cabrera said. "It kind of came out of nowhere, but I'm fine. I just need a few more games and I'll be ready."

Selected in the second round of the 2010 First-Year Player Draft, Cabrera hit .231 with six home runs and 47 RBIs for Burlington last season. The organization could eventually move him to third base, but would prefer to keep him at shortstop as long as possible.

"[The injury] is not uncommon in athletes and there is no surgery required," A's director of player development Keith Lieppman said. "He just had to strengthen it and get some time off. It should not be an issue."

A scout's view of Triple-A New Orleans

A trip to New Orleans can be a whole lot of fun. But for a professional scout, it's a time to check in on the top team in the Miami Marlins' farm system.

Most of the talent in the organization resides at the lower levels, with just three of the Marlins' Top 20 Prospects playing for the Zephyrs: lefty reliever Dan Jennings (No. 20), who's seen time in the big leagues, outfielder Kevin Mattison (No. 11) and Matt Dominguez (No. 2), the third baseman now firmly blocked by Hanley Ramirez.

Dominguez is still ranked in the overall Top 100 (at No. 82), but he may not be there for that much longer.

The being stuck part isn't in his control and doesn't impact his prospect standing. And he is just 22 years old playing in Triple-A.

What he does with the bat, however, does have an impact. That's been the issue with Dominguez since the Marlins drafted him in the first round in 2007. So far this year, Dominguez has hit .231 with three homers and 21 RBIs. He has a .628 OPS -- not exactly what you want from a corner infielder. It's seemed that every time Dominguez starts to appear to figure things out offensively, he either takes a step back or gets hurt.

"[Dominguez] won't profile power-wise for a third baseman," said a scout who saw him in New Orleans recently. "Maybe he'll hit. Could he play every day for a club that mashes behind the plate and at second base? Yes, but he probably won't ever provide the power production at third."

The glove, however, has never been in question.

"He can flat play third base," the scout said.

Right-hander Tom Koehler isn't in the Top 20, but this scout was intrigued by what he saw. Koehler's been a starter in the Minors since being an 18th-round Draft pick out of SUNY-Stony Brook in 2008. He had a huge year in Double-A in 2010, but finished with a 4.97 ERA last season with New Orleans. He's fared much better this year with the Zephyrs, posting a 3.79 ERA over his seven starts.

Most have seen Koehler as a back-of-the-rotation type, and the 25-year-old might still have that future, especially if he can get back to his 2010 walk rate. But the scout saw more.

"He could be a fifth starter, but I think he could be a really good seventh-inning guy," the scout said. "He has a 60 curve (on the scouting scale of 20-80). Everything would play up. There's some Aaron Crow in him coming out of the bullpen."

Brewers watching prospects' injury progress

He went 0-for-4, but there's no doubt the Brewers' Nick Ramirez will take it.

It was Ramirez's first game of the 2012 season. Milwaukee's fourth-round pick from the 2011 First-year Player Draft had been rehabbing from a broken hamate bone.

The Cal State Fullerton product played in the Pioneer League and Midwest League last summer, hitting a combined .271 with 11 homers and 53 RBIs in 59 games. If the 22-year-old can get in a groove, don't be surprised to see him start moving more quickly. And you can read all about as he contributes to the prospect blog, We the Prospects.

Ramirez isn't the only Brewers prospect on the injury transaction wire. Khris Davis, No. 13 on the team's Top 20 Prospects list, hit the DL on Sunday with a leg injury. It was bad timing, as Davis' .328 average would be good for third in the Double-A Southern League, and his .451 OBP would top the circuit.

Many happy returns: Manny Banuelos, who is ranked No. 11 on the overall Top 100 prospects list (No. 1 on the Yankees' Top 20) returned from his back problems, and it looks like the rest did him some good. The lefty has tossed 8 1/3 innings, allowing just one run on six hits. Most importantly, he hasn't walked anyone after issuing seven free passes over his first 5 1/3 innings. ... Speaking of New York pitching prospects, Zack Wheeler (No. 26 overall, No. 1 on the Mets' Top 20) returned from his finger nail issue, going five innings and allowing two runs on six hits. He walked one and struck out seven.