Ummm...the shift problem "could" be the rod, but that's one tough sucker, I'd check your fluid level first. You know, flush, replace, yada....
If you're going to check the rod itself, put the bike on a rear stand, remove left side fairing, move the coolant bottle to the left as you face the left side. I usually swaps holes, and hang it on the forward, threaded hole. Disconnect speed sensor on side of sprocket cover, small allen head and swing it out of the way. Take a 10mm wrench and loosen the bolt on the shifter linkage that connects it to the transmission. Remov it and slide linkage off of shaft and let hang. Take a 12mm wrench, and a 12mm socket w/ ratchet and remove sidestand sensor. Now that the wires and stuff's out of the way, take a 8mm socket on a 1/4" drive with extension and take out four screws that secure cover on side of transmission. Slide cover slowly off, and inspect rod. On a rear stand you can actually remove the rod without much oil loss, but if leaning to left on side-stand, it will leak oil. See that rod is clean and inserts smoothly without much resistance.
Now replace in reverse order.....is it shifting hard at the foot, or is the lever hard to pull in
?
My bad...I thought you meant the clutch rod, are you referring to the shift "forks"...