At the end of last season, Cubs president of baseball operations Theo Epstein acknowledged his team needed more pitching. He even said he was willing to move some of the Cubs’ young position players to get it. Instead, the Cubs were able to hang onto their talented core. The team’s pitchers and catchers will hold their first workout on Wednesday. Assuming Yu Darvish passes his physical, he is expected to join the group — after agreeing to a six-year, $126-million contract.