After back-to-back games against top-8 teams Penn State and Michigan,  it seemed a few weeks back that this game with Purdue would be a bit of a breather. No so, anymore.

Purdue started the season 0-3, and looked like a team in complete free-fall, even though the losses — all at home — were by a combined eight points. They’ve since won four in a row, including a hugely impressive 49-20 win over Ohio State last Saturday. So, yes, it’s game on. (Noon ET; TV: ESPN)

Here’s what I’d like to see from the Spartans this weekend against Purdue:

Somehow survive the injury bug

Wide receiver Felton Davis III is out for the year and fellow pass catchers Cody White (hand) and Laress Nelson (leg) are still big question marks. That’s an area of concern. So is the offensive line, which has been patching things here and there all season. Quarterback Brian Lewerke played hurt all game last Saturday in the loss to Michigan, and posted some horrible numbers. What all that means is that it’s next man up, and other guys need to step up and make some plays.

Get something out of the quarterback position

With Lewerke’s shoulder hurting, he was able to throw for only 66 yards against Michigan, and he completed just 5 of 25 passes. The offense, which hasn’t been very good, had only 94 total yards. It’s been a constant thread with all the injuries, and it shows in the numbers. The Spartans are ranked No. 121 out of 129 teams in rushing (107.6 yards per game), 126th in third-down conversions (31.0 percent), 107th in total offense (351.6 yards) and 107th in scoring (23.4 points). That’s not good, but the Boilermakers aren’t very good on defense either, giving up 433.1 yards per game (103rd nationally). So the Spartans do have a chance to move the ball, and they’ll need to do it against such a high-powered offense. Hopefully it’s Lewerke, but if not, the backups need to come through.

Take the run away to make Purdue one-dimensional …

Michigan knocked the Spartans off the top spot in the nation in run defense after Karan Higdon had a big day with 144 yards last week. The Spartans are trending downward — 388 of its 557 rushing yards allowed came in the last two weeks — and that needs to change right away against Purdue. D.J. Knox has 668 yards and eight touchdowns so far, and that’s an area that Michigan State has to shut down immediately.

… But then make some big plays in the secondary

Michigan State’s pass defense has been awful all year, ranking No. 115 nationally by allowing 275.7 yards per game. Purdue averages 514.3 yards per game, second only to Ohio State in the Big Ten, and they’re dangerous, especially throwing the ball. Quarterback David Blough is very good, having thrown for 13 touchdowns and just two interceptions in this last five games. He will be a challenge, but that’s where you can surprise, making big plays when Blough goes after Michigan State’s corners.

And then find a way late to pull out a win

Despite giving up a lot of yards. Michigan State’s defense has been able to create interceptions. The Spartans haven nine picks on the season, ranked 15th in the country and third in the Big Ten. Senior safety Khari Willis has two interceptions, and seven others each have one. Purdue has been careful with the ball lately, but to win this game, Michigan State’s defense needs a turnover late so the Spartans can score on a short field to win.