Angels’ chances of getting top pitcher before deadline are slim

Zack Greinke is available and enticing, and James Shields remains a target, but the Angels’ chances of acquiring a top-flight starter before Tuesday’s nonwaiver trade deadline “are below 50% right now,” according to a person familiar with the team’s thinking but not authorized to speak publicly about it.

With an extra wild card boosting the number of playoff contenders, there are far more buyers — including prospect-rich Texas — than sellers, “and that’s really limiting what you can do,” the person said.

The Angels have a shortage of top prospects, and General Manager Jerry Dipoto would prefer not to deal his best two trade chips, pitcher Garrett Richards and center fielder Peter Bourjos. There also appears to be little wiggle room to add to a $154-million payroll.

The Angels are among several teams interested in Greinke, who is 9-3 with a 3.44 earned-run average, but the risk in acquiring the 2009 American League Cy Young Award winner is that he can depart as a free agent next winter with the team that acquires him receiving no draft-pick compensation.

The benefit for an Angels rotation weakened by Dan Haren’s back injury and Ervin Santana’s struggles? “If you’re in a pennant race,” Milwaukee Brewers General Manager Doug Melvin told USA Today, “this guy is a difference-maker.”

The Brewers are seeking a young shortstop and pitcher to plug into the rotation for Greinke. The Angels could trade shortstop Jean Segura, one of their top prospects, but Richards is the only pitcher who fits Milwaukee’s needs.

The Angels appear willing to part with Bourjos for Shields, the Tampa Bay right-hander who is 8-7 with a 4.52 ERA and whose contract includes club options for 2013 ($9 million) and 2014 ($12 million).

The Angels are also interested in Miami right-hander Josh Johnson, but they appear to have backed off Minnesota left-hander Francisco Liriano.

The Angels could pursue a lesser starter such as Rays right-hander Wade Davis, “but I think they’re looking for a guy who could be in a playoff rotation,” the person said.

Wells to return

Outfielder Vernon Wells, who hit .348 (eight for 23) with two home runs in his first six games of a rehabilitation assignment, tweeted that Thursday would be his last game at triple-A Salt Lake, meaning he will rejoin the Angels on Friday.

Wells was the starting left fielder when he tore a ligament in his right thumb May 20, but Manager Mike Scioscia said he will return as a reserve.

Catcher Chris Iannetta, out since May 8 because of a broken right wrist and right forearm strain, also appears close to returning. He hit .263 (five for 19) in five games for Salt Lake and caught nine innings for the first time Wednesday.

Short hops

Right-hander Trevor Bell, a 2005 first-round pick who appeared in 52 games with the Angels from 2009-11, was released Thursday. He had a record of 1-6 with an 8.27 ERA at Salt Lake. … The Angels are expected to decide Friday whether shortstop Erick Aybar, who has missed four games because of a broken bone in his right foot, will go on the disabled list. … Left-hander Scott Downs, who gave up one earned run in his first 32 appearances this season, has been rocked for nine earned runs and seven hits, including two homers, in four innings of his last five games.

mike.digiovanna@latimes.com