Right-hander Jake Arrieta makes his first start in a Chicago uniform on Tuesday afternoon when the Cubs host the Milwaukee Brewers in the second game of a doubleheader at Wrigley Field.
Arrieta was a 2007 draft choice of the Baltimore Orioles and made 63 starts with them in 69 appearances before heading to the Cubs as part of a four- player trade that sent Scott Feldman to the American League.
A 10-game winner two seasons ago for Baltimore, Arrieta won just three times in 24 appearances last season and had one win in five starts for the Orioles in 2013.
He split two decisions and carried a 6.63 earned run average through four April outings, then returned for a June 17 outing - a 5-1 loss at Detroit - in what turned out to be his final appearance with the Orioles.
Arrieta, who has never faced the Brewers, was 5-3 in nine games with Baltimore's Triple-A affiliate at Norfolk before the trade, and went 1-2 in five starts with Chicago's Triple-A team at Iowa after the deal.
Milwaukee opposes him with young Texas-born righty Tyler Thornburg, who makes his first start of the season and just the fourth of a brief big-league career.
The 23-year-old had a 4.50 earned run average in eight appearances - three starts - with the Brewers at the end of 2012, and had made six relief appearances with them so far in 2013.
He held opponents scoreless in four of his initial five stints through July 22, then was nicked for four runs on seven hits in a four-inning appearance against San Diego one day later.
In the opener, Milwaukee ace Yovani Gallardo tries to rebound from a 3 2/3- inning debacle in his last appearance.
The Mexican-born righty was strafed for eight hits and six runs in the brief stint and took a 10-8 loss to the Padres at Miller Park on July 25.
He's tossed 6 1/3 scoreless innings while defeating Miami five days earlier and had won four of six decisions heading into the one-sided defeat.
Gallardo dropped a 5-4 verdict to the Cubs in Milwaukee on June 26, which dropped him to 7-3 in 15 career starts against Chicago.
The Cubs oppose him with righty Carlos Villanueva, who's dropped three straight decisions and is winless in July.
The 29-year-old picked up his second win of the year with a one-inning relief stint at Seattle on June 29, but picked up no-decisions in two subsequent appearances before dropping three in a row to St. Louis, Colorado and Arizona.
In the three games, he's allowed a combined 19 hits and 12 runs in 15 innings.
He pitched a scoreless inning of relief and was credited with a hold for the Cubs against Gallardo and the Brewers on June 26.
On Monday, Carlos Gomez singled in the game's first run in the ninth inning and Jeff Bianchi and Rickie Weeks added two-run doubles in Milwaukee's 5-0 win over the Cubs.
Cubs right-hander Jeff Samardzija, the subject of trade rumors, came off the mound to a standing ovation after allowing only three hits and fanning seven over seven innings.
Kyle Lohse limited the hosts to five hits over six frames. The opener of this four-game series was left up to the bullpen, namely Pedro Strop (1-1), who faltered in the ninth.
The Brewers entered the week with a slim 123-120 lead in the all-time series between the teams and had won five of the initial eight games played in 2013 - including four straight between April 19 and June 25.