I was about to say something similar. Sure, he's 40. His numbers last season, when compared to the Cubs bullpen, would have made him 2nd in K/9, 2nd in xFIP, 1st in WAR. He was really really good. It's definitely not fair to expect that sort of success again, but I'd pretty confidently take him over several of the pitchers the Cubs are planning to throw out there. Bullpen projections aren't super reliable, but if the Cubs grabbed Robertson, he'd be projected as the 2nd best reliever on the team. It's also not really much of a risk, since he should come around 1 year 8-10, and the Cubs seemingly don't have much left to spend money on. The idea that he would waste resources and cost the Cubs a win or two is pretty silly.