The Chicago Cubs have officially activated closer Craig Kimbrel for tonight's game against the Pittsburgh Pirates, according to MLB.com Cubs reporter Jordan Bastian:

Kimbrel was sent to the Injured List on Aug. 5 with an apparent knee injury, but he had insisted that the injury would not require much more than the minimum 10 days.

After signing a three-year, $43 million contract with the Cubs in June, Kimbrel has been very up-and-down all season. In 12 2/3 innings of work, Kimbrel has a 5.68 ERA, and he has converted 9 of 11 save opportunities.

The seven-time All-Star had been steadfast in his desire to obtain a multi-year deal, and it became clear that he was amenable to waiting until such an offer arrived. The fact that a compensatory first-round draft pick would go to the Boston Red Sox in any deal Kimbrel signed also likely dissuaded some teams from paying him top dollar, particularly considering that Kimbrel was reportedly demanding a six-year deal worth over $100 million.

Theo Epstein and co. signed Kimbrel to be the solution to Chicago's late-game woes after they had plummeted toward the bottom of the league in save percentage. And, with Kimbrel and a host of other bullpen arms on IL in recent weeks, the Cubs have struggled to close out games.

The Cubs coughed up consecutive games against the Phillies and Pirates, including a monumental collapse against Philadelphia in which the Phillies scored six runs in the ninth inning and walked off on a Bryce Harper grand slam.

Chicago enters Sunday night's game in a tie for first in the National League Central, and (amongst other things) they will need Kimbrel to round into form quickly if they hope to play additional baseball in October.