The Pittsburgh Pirates' fan base could be a little worried following the events on Monday night. Jason Grilli was removed from the game due to tightness in his right forearm.  No news on the severity of the tightness has been reported, but the Pirates have to wonder if they should add reinforcements, in case Grilli cannot return to the team. Here are some candidates as the trade deadline is nearing.

Francisco Rodriguez 
Recently rumored to being courted by the Los Angeles Dodgers, Rodriguez can take the helm as the closer in Pittsburgh. The Dodgers already have Kenley Jansen as their ninth-inning man, so the Pirates can make a push to acquire the 31-year-old right-hander. In 2013, Rodriguez is 1-1 with a 1.09 ERA and 26 strikeouts in 24.2 innings pitched. Rodriguez has not blown a save opportunity this season, closing out all 10 of his save opportunities.

Kevin Gregg 
The Chicago Cubs are selling and they are selling big. After releasing Carlos Marmol earlier in the season, the Cubs took a chance on Kevin Gregg and he has not disappointed. Gregg has converted 19 of 21 save opportunities in 2013, smoothly transitioning into the closer's role for the Cubs. He is 2-2 with a 2.80 ERA in 2013. 

Jonathan Papelbon 
Papelbon has been on the rumor mill for the past couple of months. However, when discussing Papelbon and the Philadelphia Phillies, though you will get saves, money is always an issue. The 32-year-old will be guaranteed $26 million in 2014 and 2015, with a vesting option of $13 million in 2016. Add on the remainder of this year's salary and we're talking upwards of $40 million for a closer whose velocity is clearly decreasing.

If all of this becomes a headache for the Pirates, the other option will be to promote a closer from the bullpen and work on acquiring a middle reliever. Who would be inside options?

Last night's closer was Vin Mazzaro, who has pitched pretty well out of the Pirates' bullpen. So far through 33 appearances in 2013, Mazzaro is 5-2 with a 2.62 ERA and 1.14 WHIP. There's also Mark Melancon, who used to close for the Boston Red Sox before becoming a wreck. So far in 2013, Melancon's numbers have been outstanding. He's 2-1 with a 0.97 ERA over 46.1 innings pitched. 

We will bring you updates on Grilli's injury status.