Twins' lefthander Francisco Liriano may need a solid start tonight when the Twins play at Chicago to maintain his spot in the starting rotation.  Kevin Slowey threw 5 2/3 innings of shutout baseball in a minor league rehab start Monday night.  He could return as a starter or reliever this week.  It is telling that Slowey threw 5 2/3 innings instead of 1 or 2 innings at a time.  It appears he's been stretched out giving the Twins an option to replace Liriano in the rotation.  Liriano is 1-4 with a 9.13 ERA.  The Twins may have some other starting pitching options at some point this season.  Lefthander Scott Diamond is 1-1 with a 2.81 ERA in 5 triple-A starts and top prospect Kyle Gibson is 1-1 with a 3.56 ERA in 5 starts at triple-A.